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Net Zero EnergyBuildingA Living LaboratoryCEPT University, Ahmedabad

ReportDecember 2017

Centre for Advanced Research in Building Science and Energy

A Report on

Net Zero Energy BuildingA Living Laboratory CEPT University, Ahmedabad

December, 2017

AuthorsRajan Rawal, Sanyogita Manu, Agam Shah

Centre for Advanced Research in Building Science and EnergyCEPT University, Ahmedabad

Assisting TeamAmiya Ranjan, Chinmay Patel, Shruti Saraf, Devarsh Kumar, Himani Pandya

December 2017

Publication:This report has been published by Centre for Advanced Research in Building Science and Energy (CARBSE), CEPT University.

Copyright:Any part of this report can be reproduced for non-commercial use without prior permission, provided that CARBSE is clearly acknowledged.

INzeb Report - December 2017

Funding partners

CEPT University, Ahmedabad, India Ministry for New and Renewable Energy (MNRE), Government of India Gujarat Energy Development Agency (GEDA), Government of Gujarat United States Agency for International Development (USAID)

NZEB collaborators

ANTECH Consultants Built Ecology, Australia Clanton & Associates Deep Electricals GEDA, Government of Gujarat Infi nity Technologies Mechartes, India Owens Corning, India Pankaj Dharkar Associates

R&D partners

Alliance for an Energy Effi cient economy Asahi India Glass Ltd ASHRAE, Western India Chapter Axes Studios Inc. Bayer MaterialScience Biodiversity Conservation India (Private) Ltd. Bry Air (Asia) Pvt. Ltd. ContraVolts Infotech Pvt. Ltd. Ecophit SGL Group Glazing Society of India Indo-Swiss Building Energy Effi ciency Project Infosys Technologies Ltd. Ingersoll Rand ISHRAE Lawrence Berkeley National Laboratory Loughborough University UK Neosilica Technologies Pvt. Ltd. Oorja Energy Engineering Services

Pidilite Industries Ltd. SGL Carbon Private Ltd. Shashwat Cleantech The Weidt Group, USA Tripur Builders USAID ECOIII Project Vastu-Shilpa Consultants VMS Consultants Pvt. Ltd. Volpak Systems Pvt. Ltd

Oak Ridge National Laboratory (ORNL) Owens Corning, India Paharpur Business Centre/Green Spaces Philips Electronics India Ltd. PiRhoAlpha Research Pvt. Ltd. PLUSS Polymers Pvt. Ltd. Saint-Gobain Glass India Ltd. Saint-Gobain Research India Schneider Electric India Pvt. Ltd. SE Controls Shakti Sustainable Energy Foundation (SSEF) SINTEX Industries Ltd. Skyshade Daylights Society of energy engineers and managers Suveg Electronics Uponor Wipro EcoEnergy Yogi Engineers

IINzeb Report - December 2017

Contents

Executive Summary ......................................................................................................................................................... 1

About CEPT University .................................................................................................................................................. 2

CEPT Research and Development Foundation (CRDF) .............................................................................. 3

Centre for Advanced Research in Building Science and Energy (CARBSE) .................................... 4

1. Introduction to NZEB ............................................................................................................................................... 5

2. Background .................................................................................................................................................................... 6 2.1 Geography .................................................................................................................................................................... 6

2.2 Site Information .......................................................................................................................................................... 6

2.3 Climate analysis ........................................................................................................................................................... 6

2.4 Integrated Design Process ........................................................................................................................................ 7

2.4.1 Whole Building Design approach .................................................................................................................. 8

2.4.2 Preliminary explorations ................................................................................................................................. 9

3. Analysis and Conceptual Design ..................................................................................................................... 11

3.1 Technical Potential Analysis ................................................................................................................................... 11

3.2 Thermal comfort analysis ....................................................................................................................................... 12

3.3 Building Massing and Orientation Analysis ......................................................................................................... 12

3.4 Day-lighting analysis ................................................................................................................................................ 14

3.5 Artifi cial Lighting analysis ....................................................................................................................................... 16

3.6 Natural ventilation mode analysis ......................................................................................................................... 17

3.7 HVAC systems analysis ............................................................................................................................................ 17

3.8 Photovoltaic (PV) systems analysis ....................................................................................................................... 18

4. Final Design ................................................................................................................................................................. 19

4.1 Strategies implemented ......................................................................................................................................... 19

4.2 Project timeline ........................................................................................................................................................ 21

4.3 Form and space planning ........................................................................................................................................ 21

4.4 Envelope .................................................................................................................................................................... 24

4.4.1 Material and construction details ............................................................................................................... 24

4.5 Systems ...................................................................................................................................................................... 27

4.5.1 HVAC systems ................................................................................................................................................. 27

4.5.2 Photovoltaic (PV) systems ........................................................................................................................... 30

4.5.3 Lighting and Day-lighting ............................................................................................................................. 31

5. Visual documentation ........................................................................................................................................... 32

5.1 During Construction ................................................................................................................................................ 32

5.2 Post-construction ..................................................................................................................................................... 33

IIINzeb Report - December 2017

6. Building Operation ................................................................................................................................................. 34

7. Post-construction Monitoring and Control .............................................................................................. 35

7.1 Envelope and Environment monitoring ............................................................................................................... 38

7.1.1 Data loggers for environmental parameters ........................................................................................... 39

7.1.2 Building and system level sensors .............................................................................................................. 39

7.1.3 Automatic weather station ......................................................................................................................... 40

7.2 Energy monitoring ................................................................................................................................................... 40

7.3 Occupant behavior .................................................................................................................................................. 42

7.4 Data analysis ............................................................................................................................................................. 42

7.4.1 Envelope surface temperatures ................................................................................................................. 42

7.4.2 Typical week consumption profi le ............................................................................................................. 43

7.4.3 Operation hours and occupancy patterns ................................................................................................ 46

7.4.4 Occupant Thermal comfort survey ............................................................................................................ 46

7.5 Energy Performance Index (EPI) ............................................................................................................................ 48

8. Conclusion .................................................................................................................................................................... 49

References ......................................................................................................................................................................... 50

Annexures .......................................................................................................................................................................... 51

IVNzeb Report - December 2017

List of fi gures

Figure 1: Monthly Temperature, Humidity and Wind speed from weather station at CEPT University Campus in

Ahmedabad for Apr 2014 – Mar 2015

Figure 2: Analysis of Climate, Radiation and Sky-cover

Figure 3: Design decisions during the design process

Figure 4: Methodology to Evaluate Thermal Comfort Conditioning Systems

Figure 5: Psychometric chart depicting that only 23% of the daytime hours fall in the comfort range

Figure 6: Predesign energy analysis of a benchmark building and technical potential of readily available

technologies and design approaches

Figure 7: Building elements which were evaluated for day-lighting performance

Figure 8: Daylight simulation models for Option 4: a) Initial design and b) Proposed design for noon of December

21 for clear sky conditions

Figure 9: Illuminance plans for the fi rst fl oor under clear sky

Figure 10: Continuous Daylight autonomy: Goal of 300 lux more than 70% of the time on the First fl oor

Figure 11: Electric Lighting Preliminary Design for NZEB Basement

Figure 12: Typical Annual ASHRAE 55 Operative Temperature comfort bands for Naturally ventilated spaces in

Ahmedabad, India

Figure 13: CFD model analysis for Thermal comfort with natural ventilation

Figure 14: Analysis of building cooling loads w.r.t. Building massing and orientation

Figure 15: Sectional view showing strategies in NZEB

Figure 16: NZEB exterior perspective views

Figure 17: NZEB Basement plan

Figure 18: NZEB Ground fl oor plan

Figure 19: NZEB First fl oor plan

Figure 20: NZEB Mezzanine fl oor plan

Figure 21: NZEB Terrace plan

Figure 22: NZEB Building section


Figure 24: NZEB Envelope details

Figure 25: HVAC System details


Figure 27: NZEB Terrace with PV panels

Figure 28: Parametric Simulation for System Optimization-Best opportunities for energy savings and reducing

PV capacity

Figure 29: NZEB inside view

Figure 30: Conceptual diagram of monitoring and control system through BMS in the NZEB

Figure 31: BMS interface for the whole building

Figure 32: BMS dashboard for the Basement

Figure 33: BMS dashboard for the Ground fl oor

Figure 34: BMS dashboard for the First fl oor

Figure 35: BMS dashboard for the Second fl oor

Figure 36: HOBO logger and HOBO node installed inside NZEB

Figure 37: Actual energy consumption vs. generation through PV panels for year 2016

Figure 38: Monthly Energy consumption and generation statistics in the year 2016

VNzeb Report - December 2017

Figure 39: Whisker plot of NZEB Energy consumption and generation pattern (Dec 2015 – Apr 2016)

Figure 40: NZEB energy vs environment plot

Figure 41: Surface temperature (indoor and outdoor) near admin desk on fi rst fl oor

Figure 42: Surface temperature (indoor and outdoor) inside equipment chamber on fi rst fl oor

Figure 43: Hourly total energy generation and consumption profi le with outdoor and average indoor temperature

for a week before summer typical week


for summer typical week


for a week after summer typical week

Figure 46: Hourly total energy generation and consumption profi le with outdoor temperature and fl oor wise

average indoor temperature for summer typical week

Figure 47: Daily total energy generation and consumption with indoor and outdoor temperature for the year

2016-2017

Figure 48: Annual Occupancy Pattern

Figure 49: Acceptance of thermal environment by building occupants

Figure 50: Thermal sensation of building occupants

Figure 51: Comfort Vote by building occupants

List of tables

Table 1: Pre- design direction for NZEB

Table 2: Opportunities and challenges for Massing options

Table 3: Envelope details

Table 4: Details of monitoring and control strategies

Table 5: Total number of sensors

Table 6: Operating hours of various systems

VINzeb Report - December 2017

Abbreviations

AWS: Automatic Weather Station

BMS: Building Management System

CFD: Computational Fluid Dynamics

DGU: Double Glazed Unit

ECBC: Energy Conservation and Building Code

GEDA: Gujarat Energy Development Agency

GRIHA: Green Rating for Integrated Habitat Assessment

HVAC: Heating, Ventilation and Air-conditioning

LEED: Leadership in Energy and Environmental Design

MNRE: Ministry for New and Renewable Energy

NZEB: Net-zero Energy Building

PMV: Predicted Mean Vote

PPD: Predicted Percentage Dissatisfi ed

PV: Photovoltaic

TCC: Thermal Comfort Chamber

USAID: United States Agency for International Development

VLT: Visible Light Transmission

VIINzeb Report - December 2017

A net-zero energy building (NZEB) is a building with zero net energy consumption. In such a building, energy consumed is equal or sometimes less than the energy generated by renewable energy technologies installed on site. Various passive and active strategies are deployed to ensure that the building consumes as less energy as possible but works effi ciently at the same time. Considering that buildings consume the maximum energy in a city, NZEBs can be a signifi cant step towards building energy effi ciency.

CEPT University in Ahmedabad, one of India’s premier institutes, initiated the proposal of constructing a NZEB on its campus. The Centre for Advanced research in Building science and energy (CARBSE) took up this challenging task for creation and dissemination of knowledge for energy effi cient and sustainable built environment in areas of building envelop design, testing the performance of envelope components such as fenestration and building energy simulation research. CARBSE was successful in forming a group of dedicated and enthusiastic researchers and professionals from around the world, who worked collaboratively to come up with a state-of-the-art NZEB building which would not only function as a living laboratory but also house CARBSE’s various equipment for testing and characterization services.

To start with, a thorough analysis was done of Ahmedabad’s climate and the site on which the building was proposed to be constructed. An integrated and interactive design approach was considered suitable for designing the building. An extensive pre-design analysis was done to comprehend the challenges and come up with applicable solutions for building massing, orientation, day-lighting and artifi cial lighting inside the building, natural ventilation, occupant thermal comfort, HVAC and renewable energy systems. Diff erent options were considered for building design and simulation models were designed for in-depth and detailed analysis. After a substantial amount of

brainstorming by the academia and industry experts, the design was fi nalized and construction began in September 2012 and fi nished in March 2015.

Various high level sensors were incorporated during the construction phase to monitor the performance of the building envelope, environment and systems. They are collectively monitored through a Building Management system (BMS). The indoor environment can also be controlled with the help of BMS. The data collected by the BMS has been analyzed to judge the actual performance of the building.

Some of the lessons learnt while executing this one-of-its-kind project is that the team responsible for execution of the project should have signifi cant understanding and experience in the fi eld of energy effi ciency. For a project like NZEB, site supervision is the key to ensure that all the systems – Envelope, HVAC, BMS – are installed as per design. Comprehensive checks such as inspecting envelope and building systems using thermal imaging camera, calibration of sensors, etc. have be conducted during execution and commissioning stage. Providing additional training to installation teams may be required in certain cases.

NZEB had been envisioned to provide an experience that will enable the occupants and visitors to understand the importance of resource effi ciency through sensorial aspects of design. The spaces within the facility house various activities and provide varying visual and thermal comfort experiences to enhance the user’s understanding of the perceived physical and psychological comfort conditions. It also off ers an opportunity to demonstrate strategies used to achieve the targeted comfort levels. The design, as a whole, emphasizes the importance of integrated design process and demonstrate the symbiotic relationship between architecture, interior architecture, structure and services.

Executive Summary

1Nzeb Report - December 2017

About CEPT University

CEPT University is a premier university in India focusing on design and management of human habitat. The University campus came into existence in 1962 and incorporated the language of the Modernist approach expressed in the open naturally ventilated studios, classrooms with double-height spaces for stack ventilation, and deep overhangs.Its teaching programs aim to build thoughtful professionals and its research programs deepen understanding of human settlements. The belief that educating professionals requires practicing professionals and academics to work closely together, fi rmly underpins CEPT University’s pedagogic philosophy. Therefore, CEPT University works as a collaborative of academics and practitioners. Practitioners adept at decision-making bring their experience to classrooms and academics impart a more thoughtful and critical approach. CEPT University also undertakes advisory projects to further the goal of making habitats more livable. Through its education, research and advisory activities, CEPT strives to improve the impact of habitat professions in enriching the lives of people in India's villages, towns and cities.

The University comprises of fi ve faculties. The Faculty of Architecture was established as the 'School of

Architecture' in 1962. It focuses on design in the private realm. The Faculty of Planning, focused on planning in the public realm, was established in 1972 as the 'School of Planning'. The Faculty of Technology, which concentrates on engineering and construction, was established in 1982 as the 'School of Building Science and Technology'. The Faculty of Design was established in 1991 as the 'School of Interior Design'. It deals with habitat related interiors, crafts, systems, and products. Faculty of Management was established in 2013 and it focuses on Habitat and Project Management.

CEPT University takes its name from the 'Centre for Environmental Planning and Technology'. CEPT and the various schools that it comprises were established by the Ahmedabad Education Society with the support of the Government of Gujarat and the Government of India. The Government of Gujarat incorporated CEPT as a university in 2005. In 2007 the University Grants Commission recognized CEPT University under section 2(f) of the UGC Act, 1956. The Department of Scientifi c and Industrial Research (DSIR) of the Government of India recognizes the University as a Scientifi c and Industrial Research Organization (SIRO). (http://cept.ac.in/about/cept-university, 2017)


CEPT Research and Development Foundation (CRDF)

Besides off ering education in varied streams, CEPT University has established centers to conduct research and developmental activities and consultancy. These centers interact with industry, government organizations and public at large to generate and disseminate knowledge pertaining to built environment. CEPT Research and Development Foundation (CRDF) manages these consulting, contract research and capacity building activities. CRDF is organized under thematic groups (or verticals). Each thematic group is focused on a specifi c area of study and research. The centers which have been established under CRDF are:a. Center for Urban Equity (CUE)b. Centre for Advanced Research in Building Science

and Energy (CARBSE)

c. Design Innovation and Craft Resource Center (DICRC)

d. Center for Excellence in Urban Transport (CoE)e. Center for Professional Development (CPD)f. Center for Urban Land & Real Estate Policy

(CULREP)g. Center for Water and Sanitation (C-WAS)

Each group has a full time coordinator who manages the various research and consulting projects to be undertaken by the group. Various faculty members and students benefi t by participating in these research and consulting projects. CRDF is led by an independent board and managed by its Director. (http://cept.ac.in/cept-research-development-foundation-crdf, 2017)


Centre for Advanced Research in Building Science and Energy (CARBSE)

Within India, the building sector uses more than one-third of the national energy use in India, and with further growth in this sector, India faces a formidable challenge in reducing its dependence on fossil fuels, natural resources and energy supply infrastructure. Buildings and cities in other emerging economies are also being challenged by such context. CARBSE at CEPT aims to serve society by providing impetus for creation and dissemination of knowledge for energy effi cient and sustainable built environment by working dedicatedly in areas of building envelop design, testing the performance of envelope components such as fenestration and building energy simulation research (Refer Annexure 3).

Goals Generate robust knowledge database for

strengthening of energy effi ciency as a critical focus with the built environment related fi elds

Create enhanced knowledge of construction materials, methods and practices for energy effi cient architecture in India

Extend research and dissemination activities in areas of Urban Planning and design with an integrated approach to resource planning including energy, water and land

Objectives Establish state-of-art building simulation facilities

and conduct training programs for professionals and educators

Help government to formulate and implement energy conservation policy and initiatives and also help local government to adopt ECBC and formulate local building regulations for code compliance

Build advance building envelop energy performance laboratory and establish a certifi cation and labeling program for fenestration and related products.

Construct its own building as a demonstration of best of design and technology - a living laboratory for research in energy effi cient buildings

The Center has achieved status of:

a. A 'Regional Energy Effi ciency Center' on Building Energy Effi ciency by the USAID ECO-III program

b. 'Center of Excellence for Solar Passive Architecture and Green Building Technologies' by the Ministry of New and Renewable Energy, Government of India.

c. CARBSE led the prestigious US-India clean energy research and development project for building energy effi ciency titled ‘Center for Building Energy Research and Development’ (CBERD).

d. CARBSE is supported by Gujarat Energy Development Agency, Shakti Sustainable Energy Foundation (SSEF), industry and various philanthropic organizations. (http://cept.ac.in/center-for-advanced-research-in-building-science-energy-carbse, 2017)

One of the many objectives of CARBSE was to construct a research facility demonstrating best of design and technology – a living laboratory for research in energy effi cient buildings where it wanted to house its laboratory testing equipment that will characterize performance of high effi ciency components, establish certifi cation and labeling program for fenestrations & related products, conduct thermal comfort experiments in a thermal comfort chamber, establish a state-of-the-art artifi cial sky simulator and conduct workshops and dissemination activities in the area of building energy effi ciency and related fi elds. Furthermore, there was also a need to provide comfortable workstations for CARBSE’s expanding number of researchers and research scholars. In order to fulfi ll this objective, the idea of building an ultra-effi cient Net Zero Energy (NZE) Building at CEPT University campus, was conceptualized and implemented. (http://www.carbse.org, 2017)


01INTRODUCTION TO NZEB


Amid emerging covers evolving energy prices, energy independence, impact of climate change and the statistics refl ect buildings are the primary consumer in India. Signifi cant amount of energy can be reduced in building sector by integrating energy effi cient strategies into the design, construction and the operation of new buildings as well as undertaking retrofi ts to improve the effi ciency of existing buildings. The hypothesis of Net Zero Energy Building (NZEB), a building which generates as much energy as it uses over the duration of one whole year, has been evolving from research to reality. (Behera, Rawal, & Shukla, 2016)

Objectives of the building facility to house CARBSE were:

Demonstration of low energy building design to achieve Net Zero Energy building

Research and practice of appropriate strategies to achieve thermal comfort

Harness and maximize the usage of daylight Integrate renewable energy sources as part of

architectural design Monitoring of buildings for their energy effi ciency

potential by in-house research scholars and use the collected data to develop a comprehensive database accessible to all

Use of low embodied energy materials and innovative structural system

The architect’s - Prof. Balkrishna V. Doshi - vision of the REEC building was aimed at re-establishing the context and importance of sustainable low energy architecture. Since the building is part of the academic and research environment, it was imperative that it not only demonstrate the design and practice of sustainability but also inspire next generation of professionals.

NZEB at CEPT University campus in Ahmedabad, Gujarat, was designed to translate CARBSE’s physical working space into living-laboratory where the

architectural elements and systems components have a degree of fl exibility built-in to allow for experimentation with diff erent systems and operation strategies. NZEB houses the Centre for Advanced Research in Building Science and Energy (CARBSE). In the building, energy consumption has been reduced by 86% compared to business-as-usual buildings in the university through passive and active energy-effi ciency measures. The rest of the energy use is balanced by high effi ciency Solar PV system. The building design has only incorporated “market-ready” technologies to demonstrate that the net-zero energy building design can be propagated in the market with proper design and execution. (UNEP, 2014)

A team formed under USAID’s ECO-III Project with expert consultants from across the world and local consultants’ experiences in execution proposed a highly optimized yet, context-appropriate solution. An iterative process and exchange of ideas between a master architect, a design, construction and commissioning team that eventually occupied the building, other consultants, and equipment and material suppliers worked together in the evolution of the building design. The design of the comfort systems and energy monitoring systems for the building formed an important demonstration of the collaboration between academia and industry which is not a usual practice in India. The building itself was intended to off er opportunities to scholars, researcher, industry, and students to experiment with design and technologies, as a test bed not only during the design and construction phase, but also during its operation and usage. The total cost of implementation was ₹ 22 million. The building serves as an example of the challenges and opportunities that integrated design off ers and is a tangible example for architecture students, professionals, researchers and industry, who are going to play a vital role in the making of high performance buildings in future. (Rawal, Vaidya, Manu, & Shukla, 2015)

02BACKGROUND


2.1 GeographyAhmedabad is located at 23.03°N and 72.58°E in western India at an elevation of 53 mts. The city sits on the banks of the River Sabarmati, in north-central Gujarat. It spans an area of 464 sq. km. According to the Bureau of Indian Standards, the town falls under seismic zone-III, in a scale of I to V (in order of increasing vulnerability to earthquakes).

Ahmedabad is divided by the Sabarmati into two physically distinct eastern and western regions. The eastern bank of the river houses the old city, which includes the central town of Bhadra. This part of Ahmedabad is characterised by packed bazaars, the clustered and barricaded pol system of close clustered buildings, and numerous places of worship. It houses the main railway station, the General Post Offi ce, and few buildings of the Muzaff arid and British eras. The colonial period saw the expansion of the city to the western side of Sabarmati, facilitated by the construction of Ellis Bridge in 1875 and later with the modern Nehru Bridge. This part of the city houses educational institutions, modern buildings, well-planned residential areas, shopping malls, multiplexes and new business districts.

2.2 Site InformationCEPT University campus is located at the Kasturbhai Lalbhai Campus in Navranpura, a much larger campus of the Ahmedabad Education Society (AES). CEPT University is housed in an area of about 80,000 sq. m. The AES colleges of arts, science, commerce, business management and pharmacy and Vikram A. Sarabhai Community Science Centre, Kanoria Centre for Arts and Hutheesing Visual Arts Centre are located in the vicinity. There are over 8000 sq. m. of studios, lecture halls, theatre, workshops, laboratories, library and computer centres and general activity spaces. (Refer Annexure 1)

The campus receives electricity supply from grid from Torrent Power. It is a designated consumer having connected load of 275 kVA. 315 kVA transformer is located on CEPT University campus. Campus receives its water supply from the Ahmedabad Municipal Corporation, its daily usage about 6000 litres. It has underground and overhead water tank for storage. CEPT University campus is 0.3 km from the municipal transport bus stand and 1.1 km from Bus Rapid Transit System. It is 11 km away from international and domestic airport and 4 km from the Railway station.

2.3 Climate analysisAhmedabad has a hot semi-arid climate (Köppen climate classifi cation BSh). There are three main seasons: summer, monsoon and winter. Aside from the monsoon season, the climate is dry. The weather is hot through the months of March to June - the average summer maximum is 45°C (113°F), and the average minimum is 23°C (73°F). From November to February, the average maximum temperature is 30°C (85°F), the average minimum is 15°C (59°F), and the climate is extremely dry. Cold northerly winds are responsible for a mild chill in January. The southwest monsoon brings a humid climate from mid-June to mid-September. The average annual rainfall is about 76.0 cm (36.7 inches), but infrequent heavy torrential rains cause the river to fl ood. The highest temperature recorded is 47°C (116.6°F) and the lowest is 5°C (41°F). On 21 May 2010, mercury touched 46.8°C (116.24°F), making highest temperature recorded in last 40 years in Ahmedabad. In recent years, Ahmedabad has suff ered from increasing air, water and soil pollution from neighboring industrial areas and textile mills. (CEPT & ECO-III, 2010)

Figure 1: Monthly Temperature, Humidity and Wind speed from weather station at CEPT University Campus in Ahmedabad for Apr 2014 – Mar 2015 (Rawal, Vaidya, Manu, & Shukla, 2015)

Figure 2: Climate analysis: a) Sunpath Diagram b) Solar Radiation and c) Cloud-cover (Vaidya & Ghatti, 2017)

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2.4 Integrated Design ProcessIntegrated design process was followed during design phase of building. Three design charrettes were conducted with participation from client – promoters, building users, architects, sustainability experts, energy analysts, HVAC, lighting and structure consultants,

contractors and legal experts. Each charrette was conducted over two to three days. Each charrette was followed by online meetings and a total of about 30 such meetings were conducted over 12 months. During these meetings, planners and facilitators used


strategic planning to overcome confl ict. Part of their strategy was to focus on the big picture and the details of the project to produce collaborative agreement about specifi c goals, strategies, and project priorities. Charrettes established trust, built consensus, and helped to obtain project approval more quickly by allowing participants to be a part of the decision-making process.

There were many benefi ts of using charrettes early in the design process. Most importantly, charrettes saved time and money while improving project performance. The Integrated design (ID) charrettes provided a forum for those who can infl uence design decisions to meet and begin planning the project, encouraged agreement about project goals, kicked off the design process by soliciting ideas, issues, and concerns for the project design to help avoid later iterative redesign activities. Also, they promoted enthusiasm for the project and resulted in early direction for the project outcome. Understanding Whole Building Design concepts enabled professionals to think and design the building in an integrated fashion to meet the contextual, aesthetic, programmatic, and performance requirements of the project.

2.4.1 Whole Building Design approachWhole Building Design consisted of two components: an integrated design approach and an integrated team process. The ‘integrated’ design approach asked all the members of the building stakeholder community, and the technical planning, design, and construction team to look at the project objectives, and building materials, systems, and assemblies from many diff erent perspectives. This approach was a deviation from the typical planning and design process of relying on the expertise of specialists who work in their respective specialties somewhat isolated from each other. Whole Building design in practice also requires an integrated team process in which the design team and all aff ected stakeholders work together throughout the project phases and to evaluate the design for cost, quality-of-life, future fl exibility, effi ciency; overall environmental impact; productivity, creativity; and how the occupants will be enlivened. The 'Whole Buildings' process drew from the knowledge pool of all the stakeholders across the life cycle of the project, from defi ning the need for the building, through planning, design, construction, building occupancy, and operations.

Design Objectives of Whole Building DesignIn buildings, to achieve a truly successful holistic

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project, these design objectives must be considered in concert with each other: Aesthetics: Pertains to the physical appearance

and image of building elements and spaces as well as the integrated design process.

Functional/Operational: Pertains to functional programming spatial needs and requirements, system performance as well as durability and effi cient maintenance of building elements.

Sustainable: Pertains to environmental performance of building elements and strategies.

Cost-Eff ective: Pertains to selecting building elements on the basis of life-cycle costs (weighing options during concepts, design development, and value engineering) as well as basic cost estimating and budget control.

Productive: Pertains to occupants' well-being physical and psychological comfort including building elements such as air distribution, lighting, workspaces, systems, and technology.

Secure/Safe: Pertains to the physical protection of occupants and assets from man-made and natural hazards.

Accessible: Pertains to building elements, heights and clearances implemented to address the specifi c needs of disabled people.

Historic Preservation: Pertains to specifi c actions within a historic district or aff ecting a historic building whereby building elements and strategies are classifi able into one of the four approaches: preservation, rehabilitation, restoration, or reconstruction.

As part of the Integrated Design approach, the project goals were identifi ed early on and held in proper balance during the design process; their interrelationships and interdependencies with all building systems were understood, evaluated, appropriately applied,


and coordinated concurrently from the planning and programming phase. A high-performance building cannot be achieved unless the integrated and interactive design approach is employed. It meant that all the stakeholders - everyone involved in the planning, design, use, construction, operation, and maintenance of the facility - must fully understand the issues and concerns of all the other parties and interact closely throughout all phases of the project. A focused and collaborative brainstorming session held at the beginning of the project encouraged an exchange of ideas and information and allowed truly integrated design solutions to take form. Team members - all the stakeholders - were encouraged to cross fertilize and address problems beyond their fi eld of expertise. This approach was particularly helpful in complex situations where many people represented the interests of the client and diverse needs and constituencies. Participants were educated about the issues and resolution enabled them to buy into the schematic solutions. Often interdependent issues were explored.

2.4.2 Preliminary explorations Initial Building Simulation Studies: The Weidt

Group presented the results of pre-design energy simulations for a benchmark building that had a matching building program located in Ahmedabad. These simulations were used to understand the impact of various loads on the building and assess opportunities for energy savings. The simulation set included a large variety of energy conservation strategies. The team formulated pre-design bundles of these strategies using an interactive tool to understand how far known energy effi ciency measures can reduce the energy

consumption of the building. In parallel with this, a net-zero scoping tool was used to understand the potential for onsite energy generation. The scoping of energy generation in combination with the pre-design strategy bundles was used so that the team could agree upon the design parameters that set the direction of design for NZEB at CEPT.

Thermal Comfort Conditioning Concepts and Responses: The primary purpose of a building is to provide comfort to its occupants. Though comfort requirements could vary based on various factors such as adaptability of humans to diff erent climatic conditions. An internationally-accepted defi nition of thermal comfort, used by ASHRAE, is ‘that condition of mind which expresses satisfaction with the thermal environment’. Perceptions of the thermal environment are aff ected by air temperature, radiant temperature, relative humidity, air velocity, activity and clothing. However fi eld surveys of thermal comfort demonstrate that people are more tolerant of temperature changes if they are provided the ability to control their environment, this approach widely known as the adaptive approach, is one that CARBSE incorporated in NZEB design.

Thermal comfort also emerges as a signifi cant factor that contributes to energy consumption as an outcome of the Heating Ventilation Air-conditioning and Ventilation (HVAC) systems selected in a building. Therefore, the NZEB followed a methodology highlighted in Figure 1to evaluate thermal comfort conditioning systems while optimizing the energy consumption of the building aligning to its aim of achieving a net zero energy building. The methodology

External Factors (Climate)TemperatureRelative humiditySolar radiationWind speed and directionMiscellaneous factors

Appropriate orientation

Shading devices Daylight design Thermal mass

(time lag)

Fans Evaporative

coolers Air conditioners

Internal Factors (Loads)PeopleEquipmentsLights

PassiveStrategies

ActiveStrategies

Optimizing energy use for thermal comfort

Figure 4: Methodology to Evaluate Thermal Comfort Conditioning Systems


was a stepped approach leading to the reduction in energy consumption at each step. The methodology included:1. Understanding External and Internal FactorsComprehensive analysis was undertaken to understand the climatic conditions of Ahmedabad and how they couple with the internal loads of the building to determine the cooling and ventilation requirements of the building.2. Exploring Passive StrategiesClimatic analysis coupled with thermal comfort conditioning set a platform for the team to explore appropriate passive strategies that could be incorporated in the building to provide comfort and

reduce the energy consumption. Psychometric studies were undertaken highlighting the occupied hours outside comfort range providing an opportunity to identify passive strategies and to evaluate the extent to which they would be able to provide comfort. Some applicable passive strategies explored were building shading, natural ventilation and thermal mass.3. Exploring Active StrategiesThe team after incorporating passive strategies evaluated the occupied hours that still remained outside the comfort range. For these hours high effi ciency thermal conditioning systems were evaluated such as radiant conditioning. (CEPT & ECO-III, 2010)

Figure 5: Psychometric chart depicting that only 23% of the daytime hours fall in the comfort range (Vaidya & Ghatti, 2017)

100%

98%

Relative Humidity

Wet-Bulb Temperature

Deg. C

Dew

Po

int

Tem

per

atur

e D

eg. C

Dry-Bulb Temperature ° CH

umid

ity

Rat

ion

30

25

20

15

10

5

0 5 10 15 20 25 30 35 40 45

80% 60%

0.28

0.24

0.20

0.16

0.12

.008

.004

30

25

20

15

10

5

0


03ANALYSIS AND CONCEPTUAL DESIGN

The design team followed a process that was rigorous and front-loaded with analysis, to explore as many design decisions as possible with quantitative assessment. This led to an optimized solution with a mix of strategies and an estimated payback of two years.

The iterative and sequential design process included the following stages of analysis:

Predesign: climate analysis; technical potential energy analysis; site analysis, mutual shading from tress and surrounding buildings

Conceptual design: passive thermal comfort analysis; building massing/orientation energy analysis; HVAC system energy and life-cycle analysis

System development: building envelop optimization; windows design, fenestration shading, day lighting analysis; active system thermal comfort analysis; HVAC sizing and capacity optimization analysis; natural ventilation scheduling, CFD analysis for thermal comfort; renewable energy sources identifi cation and optimizing energy generation system

Systems optimization: individual energy conservation measures (ECM) energy analysis; bundled ECM energy analysis

Table 1: Pre- design direction for NZEB

Consumption limit

70 kWh/m2

Massing 3-1 building aspect ratio 20% WWR

Lighting Dimming control of lighting LPD 6.0W/m² Occupancy sensor controls

Plug load 30% reduction and occupancy sensor controls

HVAC Direct evaporative system Adaptive thermal comfort

standard CO₂ control of outside air

PV panels 50% roof coverage

3.1 Technical Potential AnalysisThe team previewed energy generation potential on site and established an energy consumption goal that would be less than the potential on-site generation. They reviewed energy analysis of a similar benchmark building in Ahmedabad, to understand how various ECMs would help in reducing the energy consumption. The group discussed additional design approaches to reduce the energy consumption further. These ECMs, evaluated as a bundle, provided the technical potential of savings. These strategies and approaches provided a direction for design as well as metrics for evaluation in the design process. (Rawal, Vaidya, Manu, & Shukla, 2015)


3.2 Thermal comfort analysisThe intent of the thermal comfort analysis was to understand the eff ect of variation on thermal comfort metrics such as Operative Temperatures, Predicted Mean Vote, (PMV), and Predicted Percentage Dissatisfi ed (PPD). The analysis was done in two stages:

a. Preliminary Analysis: Thermal comfort simulation was done for design days, to represent hot-dry and hot-humid days identifi ed from a TMY3 weather fi le. The design day conditions were simulated with three (3) diff erent radiant system water temperatures. Preliminary thermal comfort results were presented for Operative Temperatures, Predicted Mean Vote, (PMV), and Predicted Percentage Dissatisfi ed (PPD) to the Design Team. During the presentation meeting, the water temperature variables were narrowed down for the second stage analysis and other variables were identifi ed that aff ect thermal comfort such as opaque envelope or glazing characteristics

b. Final Analysis: Thermal comfort simulation was done for an identifi ed season or for the entire year with the identifi ed variables. Final thermal comfort results were presented for Operative Temperatures, Predicted Mean Vote (PMV), and Predicted Percentage Dissatisfi ed (PPD) to the Design Team. (TWG, Preliminary Thermal Comfort Analysis results report, 2011)

3.3 Building Massing and Orientation AnalysisThe focus of the building massing analysis was to show the impact of building shape, orientation, space programming, and passive solar aspects of the massing options. These aspects of design have an impact on the day lighting potential and the energy use of the building.

The Design team identifi ed four massing options for energy analysis. The opportunities and challenges for the massing options are shown below. HVAC zoning concepts were discussed with the design team during the introductory meeting. Each massing option has been simulated with and without dimming day-lighting controls and with unitary mechanical system approach.

Benchmark

0 50 100 150 200 250KWh/m2

237

58TechnicalPotential

Heat Cool Fan/Pump DHW Lights Equip

Table 2: Opportunities and challenges for Massing options (TWG, Building Massing Analysis Results Report: NZEB at CEPT, 2011)

Sun penetration: South facing windows in Optical lab may need interior light shelf to control direct sun. Sun penetration through West and North facing windows in the Optical and Simulation labs maybe limited due to adjacent buildings and trees.

Day lighting: Available to all the spaces. The basement areas may have reduced daylight availability from the North side due to adjacent buildings and trees.

HVAC Zoning: Non-conditioned- Circulation, Storage, Restroom Semi-conditioned- Offi ces, Conference room,

Seminar room, Simulation Lab Fully conditioned- Optical Lab

Option 1Floor Area: 514 sq. m.

Figure 6: Predesign energy analysis of a benchmark building and technical potential of readily available technologies and design

approaches (Rawal, Vaidya, Manu, & Shukla, 2015)


Sun penetration: South facing windows in Optical lab may need interior light shelf to control direct sun. Sun penetration through Northwest, Southeast and North facing windows in the Optical and Simulation labs maybe limited due to adjacent buildings and trees, but may need to be evaluated.




Sun penetration: South facing windows in Optical lab may need interior light shelf to control direct sun. Sun penetration through West and North facing windows in the Optical and Simulation labs maybe limited due to adjacent buildings and trees.






Sun penetration: South facing windows in Optical lab may need interior light shelf to control direct sun. Sun penetration through Northwest and North facing windows in the Optical and Simulation labs maybe limited due to adjacent buildings and trees, but may need to be evaluated.






Key observations after analysis: Option 3 showed the highest energy consumption

partly because of its larger fl oor area and additional window area.

Option 2 was the best with about 9000 kWh savings with daylighting controls.

Option 4 and Option 2 were very similar and the additional saving in Option 2 was a result of the location of the seminar room in the basement.

Option 1 had about 8500 KWh of savings with daylighting controls. (TWG, Building Massing Analysis Results Report: NZEB at CEPT, 2011)

3.4 Day-lighting analysisDay-lighting design became the basis of architectural massing and fenestration. Options for fenestration, shading, and materials were evaluated using multiple metrics such as illuminance under clear and overcast skies, daylight factor, useful daylight index, and daylight autonomy.

Initial Daylight model Basement: During the winter months, direct sun

through the Basement Monitor might have created glare in the Offi ce and Meeting Room if there had been no shading. The average illuminance of 8260 lux was excessive. Even in the shaded areas the illuminance was 3000 lux, which was 10 times the target illuminance.

First Floor: During the winter months, direct sun through the South View Windows would have created glare for the workstations adjacent to these windows.

Second Floor: The sloped ceiling is the key architectural feature for the fi rst and second fl oors, but was the darkest surface in the space.

Proposed Daylight model Basement: By reducing the width of the Basement

Monitor glazing and adding a light shelf to refl ect the sunlight and control glare, the average illuminance was reduced to 400 lux, which is much more reasonable.

First Floor: Tilting the exterior shading downward improved the shading for the view window, and discouraged birds from nesting. To maintain visibility through the exterior shading, perforated metal with 1mm holes spaced at 2-3mm were used.

Second Floor: Widening the second fl oor monitor improved the ceiling surface brightness for the second fl oor. Another strategy discussed in meetings (but not shown in this model) was to add a clerestory and light shelf at the bottom of the sloped ceiling to improve the brightness of this feature and benefi t both the fi rst and second fl oors. (Roederer, Sanders, & Clanton, 2011)

Figure 7: Building elements which were evaluated for day-lighting performance

Sizing of North Windows

Sizing of South Vision Windows

Sizing of Basement Light Monitor

Sizing of Basement Courtyard Windows

Sizing of Lightselves

Interior wall Finishes


Calculation Summary - Initial

Label Avg Max Min Max/Min

2nd Floor 1483 1822 1124 1.62

1st Floor 9149 49169 1542 31.89

Basement 8261 48497 1589 30.52

December 21 - Noon - Clear Sky

Calculation Summary - Proposed

Label Avg Max Min Max/Min

2nd Floor 2361 2993 1660 1.8

1st Floor 2085 3426 1342 2.55

Basement 396.24 745 149 5.01

December 21 - Noon - Clear Sky

Figure 8: Daylight simulation models for Option 4: a) Initial design and b) Proposed design for noon of December 21 for clear sky conditions (Roederer, Sanders, & Clanton, 2011)

Figure 9: Illuminance plans for the fi rst fl oor under clear sky

a)

b)


Figure 9 (a) shows the illuminance plan with 2.8m wide vision windows. It is clear that in this case, the daylight in the space was insuffi cient. Figure 9 (b) shows the illuminance plan with 1.4 m wide vision windows. Reduced width also reduced some daylight throughout the space and helped in reducing high contrast/glare near windows. But, reduced width has almost no impact on daylight autonomy.

3.5 Artifi cial Lighting analysisSince 100% of the spaces were intended to be day-lighted for 90% of the daylight hours, there had to be little to no lighting energy used during the day. At night, with a combination of controls and lower lighting power densities, energy use had to be a minimum. The design needed to be aggressive in order to meet the 90% energy reduction for a net zero energy building.

Figure 10: Continuous Daylight autonomy: Goal of 300 lux more than 70% of the time on the First fl oor (TWG, Daylighting Analysis Results Meeting: Energy Design Assistance, 2011)

Figure 11: Preliminary Design for NZEB Basement

Below are lighting design features that helped in achieving the 90%+ energy reduction goals for NZEB:

1. Incorporating lighting layers (ambient, accent and task)

2. Using indirect lighting for ambient lighting (fl uorescent and/or LED)

3. Using LED lighting for accent and task4. Designing addressable dimmable controls for all

lighting5. Incorporating vacancy and daylighting sensing6. Providing personal task light controls

Layered lighting design created beautiful architectural lighting and gives the occupants the correct amount of light for personal tasks. It also has the potential to reduce lighting power densities by 30%, as compared

With 2.8m wide vision windows

Reduced width has almonst no impact on DA

70% Goal is met

70% Goal is met

70% Goal is not met

With 1.4m widevision windows

N


to ASHRAE 90.1 2007 Baseline. Selecting appropriate luminaires, lamps, gear and controls have additional energy reduction potential of 50%.

Figure 11 shows a preliminary lighting proposal for the basement where Type T1 Track lights were expected to highlight the white-board’s vertical surface for accent lighting, Type S2 Luminaire for task lighting at each work space and Type P1 Luminaires were expected to provide the ambient lighting layer. (Clanton, 2011)

3.6 Natural ventilation mode analysis CFD modeling was done to assess the operative temperatures in the building for comfort as per ASHRAE-55 2010 (ASHRAE, 2010) for naturally ventilated spaces. The table in Figure 13 shows the results of the analysis for each month and period of the day when windows could be opened or closed to achieve thermal comfort. “No” indicated when thermal comfort could not be achieved with windows open or closed, and either a mixed mode ventilation or mechanical cooling would be required.

35

34

33

32

31

30

29

28

27

16

25

24

23

22

21

20A B C D E F G H I J K L M N V P Q R S T U V W X Y Z

Too Hot(<80% Acceptable)

Cool(80%-90% Acceptable)

Warm (80%-90% Acceptable)

Too Cold (<80% Acceptable)

Comfortable (90% Acceptable)

Mean MonthlyTemperature

Tem

per

atur

e ° C

Figure 12: Typical Annual ASHRAE 55 Operative Temperature comfort bands for Naturally ventilated spaces in Ahmedabad,

India (Taniguchi, 2011)

Figure 13: CFD model analysis for Thermal comfort with natural ventilation

Month Morning Afternoon Evening

Jan WindowClosed

WindowOpen

WindowOpen

Fab WindowClosed

WindowOpen

WindowOpen

Mar WindowOpen

No No

Apr No No No

May No No No

Jun No No No

Jul No No No

Aug No No No

Sep No No No

Oct WindowOpen

No No

Nov WindowOpen

No WindowOpen

Dec WindowClosed

WindowOpen

WindowOpen

23.00022.85022.70022.55022.40022.25022.10021.95021.80021.65021.50021.35021.20021.05020.90020.75020.60020.45020.30020.15020.000

29.00

28.50

28.00

27.50

27.00

26.50

26.00

3.7 HVAC systems analysisThe analysis utilized DOE-2.1E, a sophisticated building simulation program that performs thermal and illuminance calculations on an hour-by-hour basis. It uses typical yearly climatic data to determine the energy loads and system requirements for the building. Building description input involves defi ning

the building’s geometry including interior spaces and the building envelope.

The Weidt group made assumptions on some of the building’s characteristics since detailed information was not available early in the design stage. Such


assumptions included building materials, expected equipment load, lighting design and some aspects of the mechanical systems. Building envelope and lighting systems were modeled at the minimum levels prescribed by the energy code. Mechanical options were modeled based on discussions with the design team. The Weidt group collected information on the expected use of the building and conceptual thermal zoning of the options studied. The computer models were simulated using weather data for the building location and the expected utility rates for the project.

During the design phase, multiple HVAC options were identifi ed for the building. Based on extensive discussions with consultants, fi ve possible system types were selected for comparison. The fi nal system design of the building was selected to provide high effi ciency as well as fl exibility for research experiments.

The following options were considered for HVAC installation: Option A: Packaged DX, Constant volume Option B: Packaged DX, Variable air volume Option C: Rainwater harvest cooling + Supple

mented by pony chiller cooling Option D: Radiant cooling with ground-source

heat pump Option E: VRF system, Constant volume (TWG,

HVAC Analysis results report - Revised draft, 2011)

Building cooling loads vary with the building massing and orientation. The graphs below show the yearly cooling load for each massing option as mentioned in Table 2.

3.8 Photovoltaic (PV) systems analysis CEPT and the Design team had agreed to an energy performance goal of NZEB with 35-40 kWh/sqm. energy use intensity on the Predesign basis. At the Charrette, the team estimated the renewable energy that could be generated using PV panels on the roof of the proposed NZEB building and the adjacent School of Interior design building. The PV panels were decided to be tilted at about 23° facing due south and would generate about 157 kWh/sq m of PV panel area. Assuming 50% roof coverage for the two buildings with the PV panels, where the remaining roof area may be needed for other uses or activities, the on-site energy generation potential was estimated to be about 70kWh/sqm. Thus for the building to be net-zero, the maximum energy consumption (EPI) had to be 70kWh/sqm. This EPI was the upper limit for energy effi ciency strategies during design and operation. (TWG, Energy Design Assistance, 2011)

Option 2

Option 1

Option 4

Option 5

Walls

Infi ltration

Occupants

Roofs

Window conductance

Lights

Underground surface

Window solar

Equipment

Option 2

Option 1 15

17

16

18

24

22

31

22

21

15

29

25

17

17

17

17

13

13

13

13

34

34

34

34

1

1

2

1

1

1

1

1

2

2

2

2

Total Yearly Building Loads for Options (mWh)

Option 4

Option 5

N

Figure 14: Analysis of building cooling loads w.r.t. Building massing and orientation (Vaidya & Ghatti, 2017)


04FINAL DESIGN

4.1 Strategies implemented

Strategy 1: Building massing and orientationThe CARBSE building is designed with a 3:1 building aspect ratio (length to width ratio) with a longer East-West axis. Window to wall ratios (WWR) optimized at 26. No windows are provided on East and West façade. This optimizes daylighting and reduces heat gain. South facing 30° inclined roof with 450mm high operable clerestories at two levels provide opportunity for daylighting in addition to creating stack eff ect and providing optimum angle to install Solar Photovoltaic (SPV) panels. SPV installed over inverted structural beams on roof generate electricity and shade the roof surface with 450mm ventilated air cavity between them. 28% of fl oor space is below ground level, which substantially reduces heat ingress.

Strategy 2: Optimised building envelope characteristics with material and construction technology selectionThe building envelope has insulation on the outside and high thermal mass inside. Walls have 110mm thick exposed brick on outermost layer followed by 50mm XPS insulation and 230mm thick cement plastered brick masonry wall inside with U-value of 0.42 W/m2K. In-situ Reinforced Cement Concrete roof with 32% fl yash content has a 45mm thick 50 kg/m3 rigid urethane foam insulation on top with 50mm concrete screed and white paint with Solar Refl ective Index of 103 as protective surface . Roof assembly has U-value of 0.38 W/m2K. Intermediate fl oors such as fi rst and second level RCC slabs exposed to the outdoor environment have 50mm XPS external insulation. Construction details have been executed carefully to minimize any thermal bridging. Windows have uPVC frame with insulated double glazed unit (DGU) having low-e glass. Visual Light Transmittance (VLT) of the windows is 39% with Solar Heat Gain Coeffi cient of 0.29 (SHGC) and U value of 1.7 W/m2K.

Strategy 3: Optimized thermal and luminous indoor environmentTo enable the building to operate in natural ventilation mode, mixed mode and air-conditioned mode considering usage pattern of spaces, three types of cooling and ventilation systems have been installed. Radiant cooling is the primary cooling system. False ceiling panels made of expanded graphite with anisotropic thermal character have been used for radiant cooling. Two types of panels with pipes have been used, one type has PolyEthelyne Cross link (PEX) pipes and the other has copper pipes embedded within expanded graphite panel. These panels carry supply and return water at temperature of 16°C and 20°C respectively. Demand-controlled fresh air supply in the space is provided by staging fresh and exhaust fans. The basement fl oor is supplemented by a Dedicated Outdoor Air System (DOAS) with a Heat Recovery Wheel and Digital Scroll Cooling for providing conditioned fresh air for peak cooling periods and latent loads. The HVAC system design decouples the sensible and latent heat extraction and incorporates multiple system types in the building for effi cient operation. An air cooled scroll chiller of 8.2TR supplies chilled water to the radiant system, with an inverter controlled compressor to modulate the capacity of the chiller and provide Energy Effi ciency Ratio (EER) of 2.9, 3.7, and 4.0 at 100%, 60%, 40% capacity respectively. The fi rst and second fl oors have 8 supplementary Variable Refrigerant Flow (VRF) units for peak cooling periods and latent loads. The VRF units are 8TR with COP of 3.8, 4.52, and 6.1 at 100%, 80%, 50% capacity respectively. The digital scroll system has an EER of 3.89 for cooling.


The NZEB building is designed to maximize daylight inside the building throughout the day/year to ensure minimal dependence on artifi cial lighting. All lighting fi xtures are energy effi cient LEDs. A combination of ambient and task lighting provides the required illuminance for all the spaces. Task lights can be continuously dimmed (10-100%) as well as provide a change in correlated colour temperature (CCT) of light – this enables the users to personalize their lighting environment and save electricity.

Strategy 4: Building Energy and Indoor Environment Management, Controls and CommunicationsThe building incorporates array of high accuracy sensors and sophisticated control strategies such as demand controlled ventilation, economizer based on enthalpy, chilled water reset, heat recovery wheel optimization algorithm, and chiller performance optimization for building operation and research level monitoring. Modular and fl exible control system allows conducting various research experiments on building performance optimization. The HVAC equipment has controllers with networking capability for

continuous monitoring and control of the equipment through a BMS network. The energy meters setup to monitor energy consumption by zones and end uses are networked and linked to the BMS system for continuous monitoring. Key energy and operational parameters such as current building operation, energy generation and energy consumption of the building is continuously displayed on a screen at the fi rst fl oor. Polycrystalline SPV with effi ciency of 15.34% and capacity of 30kWp is installed on south facing sloping roof. Electricity generated from SPV is supplied to the internal grid of CEPT University campus.

Indoor Design conditions: 26°C DB, <60% Relative Humidity

Outdoor Design conditions: Cooling - 41°C dry bulb temperature, 23.2°C mean coincident wet-bulb temperature (ASHRAE 2005 Fundamentals, 1% Cooling); Dehumidifi cation - 26.6 Dew Point, 22.3 Humidity Ratio, 29.9°C mean coincident dry bulb temperature (ASHRAE 2005 Fundamentals, 2% Dehumidifi cation)

Integrated SystemSouth facing PV panels tilted to

latitude angle

North light for daylighting

Vision, clerestories, lightshleves on South bring in

diff use daylight with occupant control

Radiant cooling and DOAS integrates with natural ventilation

Stack eff ect design, chimney for natural

ventilation

Lighting LPD at 4.7 w/m2 with vacancy and daylighting controls

Climate controlled spaces zoned separately

Ground heat exchange

Optimized envelope: insulated walls and roof, effi cient windows with separate properties for vision and clerestory

Outdoor exhibit area reduces conditioned

area

Figure 15: Sectional view showing strategies in NZEB


4.2 Project timelineParameters Initially planned Actual execution

Conception July, 2011 July, 2011

Start of architectural design

October, 2011 October, 2011

Start of work on site

September, 2012

September, 2012

Project completion

December, 2014

March, 2015

4.3 Form and space planningThe NZEB has a site area of 386 sq. m. and a built up area of 800 sq. m. The long sides of the facility face due north and south.

Space layout for NZEB is distinctly divided for specifi c purposes:

Basement has a Thermal Comfort Chamber,

Seminar Room and Conference Room as well as two Courtyards on either side for providing light, ventilation and multipurpose use.

Ground Floor has a dedicated space for building systems such Chillers, AHUs, Electrical Panels along with other equipment for radiant cooling system. It also has a large multipurpose semi-open space.

First Floor houses the admin area and meeting space. Majority of the fi rst fl oor space is dedicated for equipment such as Guarded Hot Box, Climate Chamber, Single Patch Sky Simulator, Mirror Box, etc. which are integral part of the Material Testing Facility at CARBSE. It also has BMS and control panel. A bridge connects First Floor to CARBSE’s existing research facility.

Mezzanine Floor overlooks the fi rst fl oor and has workstations for researchers and meeting space.

Figure 16: NZEB exterior perspective views


Figure 17: NZEB Basement plan

Figure 18: NZEB Ground fl oor plan

Figure 19: NZEB First fl oor plan

Figure 20: NZEB Mezzanine fl oor plan


Figure 21: NZEB Roof plan




4.4 Envelope The building envelope is designed to provide an opportunity to operate building in natural ventilation, temporal mixed mode and air-conditioned mode. Successful attempt was made to downsize mechanical cooling demand and electric lighting. Walls and roof have external insulation and higher internal thermal mass. Building is targeted to provide thermal comfort as per India Model for Adaptive Thermal Comfort (IMAC) in all three modes of operation.

The ceiling concrete in the building contains fl y ash contents to minimum embodied energy of the building.

Double glazed high-effi ciency windows have been installed in the building. The operable windows have been installed near occupant sitting to provide them opportunity to get fresh air as well as to provide them adaptive measures for control.

4.4.1 Material and construction details:NZEB has a very high performance external envelope. It is a RCC frame structure with thick in-fi ll walls. All the external surfaces (exposed fl oor, wall and roof) are well insulated as well as provide high thermal mass inside.

Table 3: Envelope details

Elements Details

Exterior exposed walls 110mm of exposed brickwork on the outside followed by 50mm XPS insulation and 230mm brick wall on the inside (U = 0.42 W/m2K).

Basement Retaining wall 230mm RCC with waterproof plaster on the outside

Internal walls None; it is one open space without any opaque partitions.

Internal surfaces Plastered and painted with putty fi nish

Floor slabs Made from 150mm RCC. RCC has a 50mm cement sand bedding upon which polished Kota stone is laid. The fi rst fl oor slab, which is exposed to the outdoor conditions due to absence of an enclosure on ground fl oor, has 50mm XPS insulation at the bottom with FEWEIS fi nish on the outside (U = 0.548 W/m2K).

Roof Made of 150mm RCC with PENETRON waterproofi ng and a 45mm spray foam (PUF) insulation, geotextile sheet, 50mm concrete screed and high SRI (value 103) paint on the top (U = 0.38 W/m2K). It has inverted beams with 50mm XPS exterior insulation and 50mm concrete screed painted with high SRI paint.

Peripheral beams 100mm XPS insulation on the inside

Windows Double glazed units (DGUs) with AIS-Ecosense-Exceed-Clear vision 6mm low-e glass (VLT = 0.39; SHGC = 0.29) and 12mm air gap (U = 1.7 W/m2K).

Design detailing with a 110x150mm ledge supports exposed brick work wall and makes continuity of insulation possible. Thermal bridging around windows and other critical structural areas has been minimized. Most of the windows face south and north to minimize glare and direct solar radiation and to maximize

daylight. Windows on south have a deep projection for shading. Window-to-wall ratio (WWR) on south facade is about 10% and on north is 90%. East and west facing windows in the basement are well shaded by adjacent retaining walls and trees. (Rawal, Vaidya, Manu, & Shukla, 2015)


1.1 ROOF ASSEMBLYu - VALUE (W/m2)=0.38R - VALUE (m2 .K/W)=2.654

2mm High SRI Paint

150mm R.C.C.

12mm Plaster

45mm Spray FoamInsulation(PUF

50mm Concrete Screed

3mm Geotextile Sheet

2mm Roof Seal- Water Proofi ng Membrane

2.1 FLOOR- First Flooru - VALUE (W/m2)=0.55R - VALUE (m2 .K/W)=1.82

25mm Kota Stone50mm Cement Sand Bed

150mm R.C.C.

50mm X.P.S. Insulation6mm Feweis Plaster

Out

In

2.2 FLOOR- First Flooru - VALUE (W/m2)=0.55R - VALUE (m2 .K/W)=1.82

25mm Kota Stone50mm Cement Sand Bed

50mm X.P.S. Insulation

150mm R.C.C.12mm Cement Plaster

Out

In

1.2 ROOF ASSEMBLYu - VALUE (W/m2)=0.38R - VALUE (m2 .K/W)=2.654

2mm High SRI Paint

150mm R.C.C.

12mm Plaster

45mm Spray FoamInsulation(PUF

50mm Concrete Screed

3mm Geotextile Sheet

2mm Roof Seal- Water Proofi ng Membrane


3.1 WALL SUPER STRUCTUREu - VALUE (W/m2)=0.42R - VALUE (m2 .K/W)=2.38

12mm CementPlaster

230mm Red Brick

50mm X.P.S Insulation

110mm Red Brick

Out In

3.3 WALL BASEMENTu - VALUE (W/m2)=0.28R - VALUE (m2 .K/W)=3.59

3mm AluminumComposite Panel

18mm Plywood

100mm X.P.S Insulation

12mm Cement Plaster

200mm R.C.C.

1mm PVC Film

18mm Polymer Plaster

Out In

3.2 WALL BASEMENTu - VALUE (W/m2)=2.01R - VALUE (m2 .K/W)=0.50

12mm CementPlaster

230mm Red Brick

1mm PVC Film

18mm Polymer Plaster

Out In

3.4 WINDOWu - VALUE (W/m2)=1.70R - VALUE (m2 .K/W)=0.588

Low E Double Glass Glazing With UPVC Frame

VLT - 39% Refl ection int - 14% External -23% SF - 29% SC - 0.33 U-Value - 1.790W/m2k

Out InFigure 24: NZEB Envelope details


4.5 Systems

4.5.1 HVAC systemsThe HVAC system design separates the sensible and latent heat extraction and incorporates multiple system types for effi cient operation. Three types of cooling and ventilation systems installed are:1. Radiant cooling is the primary cooling system.

False ceiling panels made of expanded graphite with anisotropic thermal character have been used for radiant cooling. An air-cooled scroll chiller supplies chilled water to the radiant system, with an inverter controlled compressor to modulate the capacity of the chiller. Demand-controlled fresh air supply in the space is provided by staging fresh and exhaust fans.

2. The basement fl oor has a Dedicated Outdoor Air System (DOAS) with a Heat Recovery Wheel and Digital Scroll Cooling for providing conditioned fresh air for peak cooling periods and latent loads.

3. The fi rst and second fl oors have supplementary Variable Refrigerant Flow (VRF) units for peak cooling periods and latent loads.

The total air-conditioned area of the building is 416 sq.m. The building contains a radiant cooling system as a primary mode of cooling. The fi rst and second fl oor have 8 variable refrigerant fl ow (VRF) units to supplement during peak cooling periods and for latent loads. Fresh air in the space is provided by staging fresh and exhaust fans. The basement fl oor is supplemented by dedicated outdoor air units with digital scroll cooling system for bringing conditioned fresh air for peak cooling periods and latent loads. The HVAC system philosophy decouples the sensible and latent heat extraction and incorporates multiple system types in the building for effi cient operation. The secondary system has been specifi cally selected to be a non-water based variable fl ow variable capacity system to avoid installing and operating multiple chillers with diff erent set point requirements (radiant with 16/20˚C and chilled water loop with 7/12˚C).

The radiant ceiling panels are lightweight and contain expanded natural graphite materials with embedded water pipes designed for 15˚C supply and 20˚C return water temperatures. The ceiling radiant panels were selected instead of slab integrated radiant panels to decouple system and building costs as well as to provide opportunity to modify radiant panel design, layout, and operation for research. The VRF units on fi rst and second fl oor are served by 8TR outdoor units with COP of 3.8, 4.52, and 6.1 at 100%, 80%, 50% capacity respectively. The building contains silent and high effi ciency fans to directly supply fresh air as well as to exhaust air from the fi rst and second fl oors. The fans are also positioned to create an artifi cial draft to operate in night ventilation mode.

The dedicated outdoor unit (DOAS) has a heat recovery wheel to meet the fresh air requirements for the meeting rooms in the basement. This DOAS has been customized to re-circulate return air when expected benefi ts from heat recovery wheel are not signifi cant. DOAS is connected to a digital scroll system, with energy effi ciency ratio (EER) of 3.89 for cooling and COP of 4.1 for heating, as a supplemental air conditioning system. While heating is not needed in Ahmedabad, heating capability has been incorporated for research experiments.

High effi ciency air cooled scroll chiller of 8.2TR has been installed to supply chilled water to radiant system. Inverter controlled compressor in the chiller can continuously and effi ciently modulate the cooling capacity of the chiller. At 15˚C supply temperature and outdoor temperature of 35˚C, the chiller is expected to provide 2.9, 3.7, and 4.0 EER (EER EN14511) at 100%, 60%, 40% capacity respectively. High effi ciency pump with variable speed drive is integrated with the chiller to deliver chilled water through the radiant system. (Rawal, Vaidya, Manu, & Shukla, 2015)



Floor Standing Concealed Type VRF Indoor Unit

High-wall Type - VRF Indoor Unit

Radiant Panel Manifold

VRF Outdoor Unit

DC fan motor Highly effi cient DC motor Sine wave drive

Heat exchangerHigh-effi ciency R410Aheat-transfer tube

Vector-controlled inverterThe inverter boosts effi ciency by controlling R410A and a twin-rotary DC compressor.

Vector IPDU control changes the motor current wave to a smooth sine pattern so that noise emitted from the drive units is greatly reduced.

Heat exchangerIncreased, wide range effi ciency is realized.

Confi guration of the fi nnedheat-transfer tube

Heat exchangerHigh-pressurelow-volume fan

DC driven motor with rare-earth magnet- Compact- Higher effi ciency- Higher power motor torque

Precise manufacturingtechnology in thecompression parts- Higher effi ciency (in wide range)- Higher reliability

The bat wing fan realizes low sound level.

Smooth sine curve realizes higher effi ciency and less noise.

Effi cient circuit built-in;new PIM

ECOPHIT®L(Graphite lightweightconstruction panel)

Meander tube

Steel sheet ceiling(various designs)

Nonwoven

Insulation



Chiller

Pump

Digital Scroll

DOAS Outdoor Unit

1. The outdoor air probe allows setting the ideal climate in relation to environmental conditions

2. The built-in display shows all the operating parameter settings 3. The Electronic Thermostat Optimises the operation conditions

of the cooling circuit 4. The plate heat exchanger maximises the thermal effi ciency

thanks to large exchange surfaces 5. The Inverter DC Compressor allows high seasonal effi ciency

thanks to the modulation 6. The optimized fan profi le guarantees extremely quiet

operation in every operating mode. The fan varies its speed according to the conditions, increasing its quiet operation.

7. The Hydrophilic Battery ensures a better cleaning maintaining thermal exchange effi ciency and reduced defrost time


4.5.2 Photovoltaic (PV) systems NZEB solar generation started 15th Dec 2015 onwards. Solar Photovoltaic system of 30kWp capacity is installed on south facing sloping roof. The system is connected to Internal Grid of CEPT University campus and the generated electricity is used within the Campus. The system is connected with BMS for data collection and monitoring the performance. Each polycrystalline PV panel of 1975mmx990mm has rated capacity of 300Wp.

For NZEB, the data distribution of solar generation varies consistently between 80 to 160 kWh. For generation the mean always lies below median. The upper quartile of the energy generation always lies above 100 kWh. Upper quartile of consumption lies above 50 kWh. (Dec 2015- Apr 2016) (Behera, Rawal, & Shukla, 2016)

Figure 27: NZEB Terrace with PV panels

Figure 28: Parametric Simulation for System Optimization-Best opportunities for energy savings and reducing PV capacity (Vaidya & Ghatti, 2017)

0 2 4 6 8 10 12 14 0.0 1.0 2.0 3.0

Ground heat pump, High effi ciency, VFD pumping

Add evaporative fl uid cooler for rain water tank (night use)

Dimming daylighting

Air cooled chiller, with increased effi ciency @ 3.35 COP (ARI)

Occupancy sensor control of lighting

Max envelope

Lighting switch strategies

Lowest wattage lighting design

Total heat recovery

DOAS system - change to VAVS

2.9

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4.5.3 Lighting and DaylightingThe building is designed to maximize daylight inside the building throughout the year to ensure minimal dependence on artifi cial lighting and improve occupant health and wellbeing as well as productivity. All rooms in the building are designed to achieve a 75% Daylight Autonomy (continuous) for 75% of the room at 300 Lux.

Spaces are illuminated by a combination of ambient and task lighting, along with occupancy sensors. All work desks and meeting tables have LED electric task lights with personalized control. Task lights can be continuously dimmed as well as provide a change in correlated colour temperature (CCT) of light to allow the users to personalize their lighting environment. This gives excellent control to users to personalize lighting condition as well as save electricity.

Common areas and passages have wall mounted LED light fi xtures with indirect lighting for ambient illumination as well as emergency and occupancy sensors. All fi xtures have LEDs to minimize energy consumption. The average lighting power density in the building is 2.0 W/m2. The fi rst and second fl oors contain a switch in the space controlling manual, off , or auto operation of ambient lights. In auto mode, the lights in common offi ce areas and passages are turned off based on occupancy sensors. The conference and seminar rooms in the basement are also fi tted with occupancy sensors but used for monitoring only. Total connected lighting load of the building is 2196W (2.7W/m²). (Rawal, Vaidya, Manu, & Shukla, 2015)

Figure 29: NZEB inside view


05VISUAL DOCUMENTATION 5.1 During Construction

January 2013

June 2013

April 2014

May 2013

December 2013

June 2014


5.2 Post-construction


06BUILDING OPERATION

NZEB serves as a test-bed not only during the design and construction phase, but also during its operation and usage. The building operates as per the following schedule:

Offi ce: 08:30 to 18:30 hours – 250 days/yearSeminar room: 09:30 to 17:30 hours – 100 days/yearTest labs: 09:30 to 17:30 – 250 days/year

The building is either operated in natural ventilation mode, mixed mode, or mechanical system mode based on outdoor weather and indoor comfort conditions. The building operators have the ability to confi gure various indoor comfort condition algorithms (such as custom adaptive thermal comfort equation or a PMV model based algorithm) in the building control system to determine suitable indoor comfort conditions.

In natural ventilation mode, the active air-conditioning system is turned off and chimney windows are opened to create a draft to cool the building naturally.

When the indoor environment does not meet the comfort requirements for specifi ed length of time, the operation switches to mixed mode; windows are opened and artifi cial supplemental draft is also created using pedestal and exhaust fans in the building. The objective in mixed mode operation is to ensure that

the building is switched to mechanical system mode only when needed.

In mechanical system mode, the primary system (active radiant system) and fresh air fans are fi rst turned on to maintain indoor thermal comfort conditions. If the primary cooling system is unable to achieve comfort conditions in the space, secondary cooling system (VRV for the fi rst and second fl oor, and DOAS in basement) is turned on. In mechanical system mode, the building incorporates demand based ventilation controls where fresh air is modulated to maintain CO2 levels in the space.

The algorithms and conditions that are most suitable to operate the building in natural, mixed and mechanical system modes are continuously tested at the laboratory through a sophisticated Building Management System (BMS). One of the key research areas is to determine the appropriate time for switching over between the three modes. (Rawal, Vaidya, Manu, & Shukla, 2015)

Electrical system is divided into fi ve parts with separate wiring lines for each - Lighting, HVAC, Plug Loads, Equipment Loads and Solar PV Panels. This enables effi cient sub-metering using smart energy meters with RS485 communication facility for integration with BMS.


07POSTCONSTRUCTION MONITORING AND CONTROLTo achieve the goal, NZEB contains a sophisticated and fl exible control system named Building Management System (BMS) that can support continuous research experiments on building monitoring and performance optimization. The control system in the building is designed to meet the following objectives:a. To serve as a single platform for monitoring and

controls in the building

The controls in this building incorporate an array of high accuracy sensors for research level monitoring as well as sophisticated and fl exible control system for conducting various research experiments on building energy effi ciency.

Monitoring component incorporates high accuracy research grade sensors to continuously monitor building performance and occupant comfort. Air conditioning and envelop monitoring system contains built�in controllers with networking capabilities (Ethernet port) and are integrated with the building management system. Envelope, energy, and environment systems have been specifi ed with built-in controllers for integration with the building control system.

b. To provide test bed for development of new technologies and control algorithms To integrate with test chambers for eff ective operations and controls

c. As shown in Figure 30, the control system is mainly divided in four components – monitoring, integration, controls, and display.

Building controls system continuously monitors installed components and uses effi cient algorithms to optimize building performance. Key energy and operational parameters (such as building information, current operation, historical energy consumption, and current energy consumption) are continuously displayed on display screen located on the fi rst fl oor.

All plug loads in NZEB are monitored using Smart Power Strips, which provide information for device IDs, usage time, and electricity consumed for each equipment on the desk. Smart Power Strips are connected to a centralized server through Wi-Fi, which stores the data for every minute. Smart strips allow

Monitoring Integration Controls Display

Envelope HVAC OperationChiller

Environment Lighting ComfortHVAC

Energy Plug Loads ConsumptionVFD

Behavior Photovoltaic GenerationPhotovoltaic

Outdoor Operation Historical

Figure 30: Conceptual diagram of monitoring and control system through BMS in the NZEB


detailed understanding of usage pattern for various types of connected devices as well as provide load profi le for entire building to develop strategies for plug load management.

Electricity generated by solar panels and energy used in the building operations and research experiments is measured and monitored by using Smart energy meters1 connected with BMS.

1 EM6400 Schneider smart energy meters have been enabled with RS485 Modbus communication protocol. Energy meters measure True

RMS, one second update time, four quadrant power and energy. The accuracy for meters is Class 1.0 as per IEC 62052-11 and IEC 62053-21;

Class 0.5S (Optional) as per IEC 62052-11, 62053-22; Class 0.2* (optional).

Table 4: Details of monitoring and control strategies (Rawal, Vaidya, Manu, & Shukla, 2015)

System Key monitoring and control points Key control strategies

Envelope Temperature, Heat fl ux Monitoring only

Environment Air & globe temp, RH, CO2, room pressure

Adaptive, PMV, and temp/RH based algorithm; optimum building mode

Energy Voltage, current, power factor, etc. Monitoring only; energy signatures for system operation

Behaviour Window contacts, vacancy, fan operation, comfort vote

Light control, personalized control

Radiant Surface temp, dew point, valves Variable fl ow constant setpoint, constant fl ow variable setpoint

Supply and ventilation fans Pressure, fl ow, status, current, and temp Demand based ventilation

Variable refrigerant units loading, operation, power and effi ciency System operation optimization based on energy and comfort

Air cooled chiller, DX scroll, DOAS

loading, operation, power and effi ciency, Temp, RH

System optimization based on effi ciency curve and building demand

Chilled water loop Operation, power, temp Supply temp setpoint reset

Outdoor Temp, RH, wind velocity & direction, solar radiation, rain gauge

Economizer mode; optimum building mode

PV generation Temp, power, effi ciency Load distribution based on demand

Figure 31: BMS interface for the whole building


Figure 32: BMS dashboard for the Basement

Figure 33: BMS dashboard for the Ground fl oor


Figure 34: BMS dashboard for the First fl oor

Figure 35: BMS dashboard for the Second fl oor

7.1 Envelope and Environment monitoringEnvironment monitoring incorporates both indoor environment as well as outdoor environment. For NZEB, building and system level sensors along with data loggers are used for monitoring the indoor

environment and the envelope. For monitoring and recording the outdoor weather data, an Automatic Weather Station was installed at CEPT University.


7.1.1 Data loggers for environmental parametersThere are 48 sensors in the building used to measure dry bulb temperature, relative humidity, surface temperature and globe temperature which are connected with data nodes.

Dry bulb temperature, relative humidity and surface temperatureData nodes are used to measure dry bulb temperature, relative humidity and surface temperature. They wirelessly transmit the data to a centralized data collection system within a self-healing mesh network.

There are two diff erent kinds of data nodes used. One is a 4-channel wireless data node with four analog ports which is used to measure dry bulb temperature and surface temperature. The other one is a 4-channel wireless data node with DBT-RH sensor port and two additional analog ports used to measure dry bulb temperature, relative humidity and surface temperature. Both data nodes wirelessly transmit real time data to the data receiver, reducing the inconvenience associated with manual data offl oad. Also, there are data routers installed which are used to strengthen the communication within network between data nodes and data receiver. The data receiver is connected to the system through USB cable which can readout the data using the company software.

Dry bulb temperature is measured through TMC6-HD, TMC20-HD, and TMC50-HD temperature sensors. Relative humidity is measured through DBT-RH sensors (2m temperature-relative humidity sensor probe). Surface temperature is measured through TMC6-HE sensors. These three environmental parameters are measured at 15-minutes interval.

Globe temperature Data loggers are standalone devices which are used to measure globe temperature and a direct USB interface is used for launching and data readout with the help of company software. It is a four-channel data logger with one analog port which is used to measure globe temperature. Globe temperature is measured through TMC1-HD temperature sensors at 1 hour interval.

7.1.2 Building and system level sensorsThere are 357 sensors for building level and system level monitoring which are connected with BMS. These are used to measure dry bulb temperature, relative humidity, surface temperature of the envelope, globe temperature, occupancy, and CO2 at 1 minute interval. They help in monitoring and controlling the systems in the building. The data is stored and can be accessed and visualized using BMS.

2 The measurement range is -40°C to 70°C (-40°F to 158°F) for dry bulb and surface temperature and 0% to 100% for relative humidity.

The accuracy of dry bulb and surface temperature measurement is ± 0.21°C; over 0° to 50°C (± 0.38°F over 32° to 122°F). The accuracy of

relative humidity measurement is ±2.5% from 10% RH to 90% RH typical to a maximum of ±3.5% including hysteresis at 25˚C (77˚ F); ±5%

typical for RH below 10% and above 90%.

Figure 36: HOBO logger and HOBO node installed inside NZEB


In total, there are 405 sensors in NZEB as mentioned in Table 5.

Table 5: Total number of sensors

# Type Floor No. of sensors Total no. of sensors

1 BMS Sensors (Building level) All 38 357

BMS Sensors (System level) All 319

2 BMS HOBO® ZW Sensors Basement 10 42

First Floor 13

Second Floor 13

Roof 6

3 HOBO® ZW Globe Sensors First Floor 2 6

Second Floor 4

Total 405

7.1.3 Automatic weather stationOutdoor weather data is vital to analyze the performance of the NZE building. A GSM / GPRS based Automatic Weather Station (AWS) has been installed inside CEPT campus. It is a compact, modular, rugged, low-cost system for collecting meteorological data. The AWS data logger, at the heart of the system, consists of:

Air Temperature and Humidity Sensor (KDS-011) Ultrasonic Wind Speed and Direction Sensor (KDS-

101) Atmospheric Pressure Sensor (KDS-021) Global Solar Radiation Sensor (KDS-051) Tipping Bucket Rain Sensor (KDS-071)

All the environmental data is recorded hourly by the weather station and is downloaded on a monthly basis by authorized personnel.

7.2 Energy monitoringContinuous monitoring and data collection for energy and indoor environmental condition during building operation allows conducting detailed performance analysis. It also helps to calibrate simulation models. It helps in evolving optimized strategies for operation such as balancing between the use of primary (Radiant Panels) and secondary (VRF) cooling system for space conditioning. Also, it helps in comparison of energy consumption and generation through photovoltaic panels in NZEB. As depicted in Figure 37 to Figure 39, the annual solar power generation exceeds the energy consumed by the building and its systems.

The energy consumption and environmental parameters variation from October 2015 to April 2016, is shown in Figure 40 along with solar energy generation data. Here, indoor environment parameters have also been taken into consideration. HVAC for experiment indicates running of thermal comfort chamber (TCC) in NZEB, which is used to perform experiment on thermal comfort. Both outdoor and indoor temperature considered for analysis are weighted average temperature on daily basis. (Behera, Rawal, & Shukla, 2016)

Figure 37: Actual energy consumption vs. generation through PV panels for year 2016 (Vaidya & Ghatti, 2017)

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Figure 38: Monthly Energy consumption and generation statistics in the year 2016 (Vaidya & Ghatti, 2017)

Figure 39: Whisker plot of NZEB Energy consumption and generation pattern (Dec 2015 – Apr 2016) (Behera, Rawal, & Shukla, 2016)

Figure 40: NZEB energy vs environment plot

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Following things can be concluded from the graph in Figure 40:

During winter (Nov 2015 – Feb 2016), the HVAC panel consumption becomes minimum.

As the outdoor temperature increases, HVAC energy consumption increases in synchronization to that.

It can be clearly observed that solar generation is always considerably higher than the total building energy consumption.

Lighting load energy consumption is always negligible to other load energy consumption. It demonstrates the day lighting ability of the building.

HVAC consumes 50%, equipment consumes 38% and power plug consumes 12% of the total energy consumption.

At the end of April 2016, the HVAC energy consumption was a bit high as the radiant panel of the building had started on an experiment basis.

The period when data is missing indicates holidays. There was no energy consumption during that period as the building was in shutdown mode. (Behera, Rawal, & Shukla, 2016)

7.3 Occupant behavior Practice of appropriate strategies to achieve thermal comfort was one of the primary objectives of building the NZE building. The user experience and feedback on performance of the building is vital to establish the degree of success of the NZEB.

As part of post-occupancy evaluation, building users take daily surveys to provide feedback on thermal

environment and air quality. The user feedback allows the facility manager to take informed decisions for fi ne-tuning building operation to provide satisfactory and healthy workspace and save energy. As an example, based on user surveys, air motion devices had been installed adjacent to the workspaces to provide personalized control over air velocity and thermal comfort.

7.4 Data analysis In this section, the data gathered from the monitoring systems and occupant surveys over the period of a year (Sep 2016 – Aug 2017) have been analyzed under diff erent heads.

7.4.1 Envelope surface temperaturesThe building envelope is monitored by measuring surface temperature using HOBO data nodes. Following are some graphs plotted using year-long data (Sep 2016 – Aug 2017) of envelope surface temperatures of NZEB:

Near Admin desk (First fl oor)The graph shown in Figure 41 represents the variation in average, maximum and minimum value of inside and outside surface temperatures measured near admin desk on fi rst fl oor over the year. The wall in consideration faces the south direction. It can be seen that the indoor temperatures range is signifi cantly less compared to the outdoor temperature range during the summer months of April to June. During monsoon and winter season, the temperatures ride close to each other.

Figure 41: Surface temperature (indoor and outdoor) near admin desk on fi rst fl oor

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Figure 42: Surface temperature (indoor and outdoor) inside equipment chamber on fi rst fl oor

Figure 43: Hourly total energy generation and consumption profi le with outdoor and average indoor temperature for a week before summer typical week

Equipment Chamber (First fl oor)The graph shown in Figure 42 represents the variation in average, maximum and minimum value of inside and outside surface temperatures measured inside equipment chamber on fi rst fl oor. The wall in consideration faces the north direction. It can be seen

7.4.2 Typical week consumption profi le

that the indoor temperatures range is signifi cantly less compared to the outdoor temperature range specifi cally during the summer months. During other months, the temperatures ride very close to each other.

The graph shown in Figure 43 represents total energy generation and consumption with outdoor and average indoor temperature on hourly basis for a week before summer typical week (10th June 2017 to 16th June 2017).

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Timeline

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Figure 44: Hourly total energy generation and consumption profi le with outdoor and average indoor temperature for summer typical week

Figure 45: Hourly total energy generation and consumption profi le with outdoor and average indoor temperature for a week after summer typical week

The graph shown in Figure 44 represents total energy generation and consumption with outdoor and average indoor temperature on hourly basis for summer typical week (17th June 2017 to 23rd June 2017).

The graph shown in Figure 45 represents total energy generation and consumption with outdoor and average indoor temperature on hourly basis for a week after summer typical week (24th June 2017 to 30th June 2017).

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Figure 46: Hourly total energy generation and consumption profi le with outdoor temperature and fl oor wise average indoor temperature for summer typical week

Figure 47: Daily total energy generation and consumption with indoor and outdoor temperature for the year 2016-2017

The graph shown in Figure 46 represents total energy generation and consumption with indoor and outdoor temperature on hourly basis for summer typical week (17th June 2017 to 23rd June 2017) for fi rst (FF) and second (SF) fl oor.

The graph shown in Figure 47 represents total energy generation and consumption with indoor and outdoor temperature on daily basis for the year (1st September 2016 to 31st August 2017).

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17-Jun 18-Jun 19-Jun 20-Jun

Timeline

14-Jun 21-Jun 22-Jun

Sep 16 Oct 16 Nov 16 Dec 16 Jan 17 Feb 17 Mar 17

Timeline

Apr 17 May 17 Jun 17 Jul 17 Aug 17


7.4.3 Operation hours and occupancy patternsThe building operates from 08:30 hours to 18:30 hours every day except on holidays. Table 6 shows operating hours out of total 8760 annual hours for various systems.

The building was occupied for 2730 hours considering 10 working hours a day and eliminating 92 holidays in one year. On an average, NZEB is occupied by 20 users on a working day. The graph shown in Figure 48 represents the occupancy pattern – the total number of occupants present in NZEB for the period from 01 September 2016 to 31 August 2017.

Table 6: Operating hours of various systems

# System Name Operating hours (approx.)

1 Power Plug DB 2721

2 Lighting DB 47

3 Equipment Panel 6904

4 APFCR 8181

5 DX Scroll 198

6 DOAS 191

7 VRV Outdoor 1906

8 Radiant Chiller 524

9 Primary Pump 664

10 TCC Main AHU 1123

11 TCC Chiller 1146

12 TCC Personal AHU 0

Figure 48: Annual Occupancy Pattern

7.4.4 Occupant Thermal comfort surveyThermal comfort surveys3 are being taken by the occupants to evaluate occupant comfort and behavior in the building for the entire year. The survey includes 14 questions, which ask the occupants about their acceptance of thermal environment, thermal sensation, thermal comfort, air quality, air movement along with fan operation and window opening status, activities recently engaged in and clothing details.

The surveys are taken twice a week on Monday and Thursday at 11:00 hours and 16:00 hours.

The analysis of ‘right-here-right-now’ thermal comfort surveys taken by the occupants to evaluate occupant comfort and behavior in the building for the period of 8 months (from 31st January 2017 to 31st August 2017), is given below.

3 The surveys have been designed by using SurveyMonkey online survey tool. Survey response can be readout and downloaded using the

same tool.

20

18

16

14

12

10

8

6

4

2

0

Ener

gy (k

Wh)

Sep 16 Oct 16 Nov 16 Dec 16 Jan 17 Feb 17 Mar 17

Timeline

Apr 17 May 17 Jun 17 Jul 17 Aug 17




Figure 50: Thermal sensation of building occupants

Thermal sensationThe graph shown in Figure 50 represents the thermal sensation felt by the occupants. The majority of the occupants have voted that they were feeling

Acceptance of thermal environmentThe graph shown in Figure 49 represents the acceptance of thermal environment by the occupants. Each bar in the fi rst row depicts the acceptance level of the occupants at 11:00 hours on Mondays and

neutral during the time of the survey. There were few instances when some occupants were feeling warm or cool and fewer when they felt very hot or very cold.

Thursdays alternatively. The second row records their responses at 16:00 hours. It can be seen that the majority of occupants are satisfi ed with the thermal environment inside NZEB.

Time

Time

16:00 hours

16:00 hours

11:00 hours

11:00 hours

Acceptable Unacceptable Missing Data

Neutral CoolWarmVery Hot Very Cold Missing Data


Figure 51: Comfort Vote by building occupants

Comfort VoteThe graph shown in Figure 51 represents the thermal comfort felt by the occupants. The majority of the occupants have voted that they were feeling very

comfortable during the time of the survey. There were few instances when some occupants were feeling comfortable and fewer when they felt uncomfortable.

7.5 Energy Performance Index (EPI): The EPI is expressed in kWh/m2 which measures the total energy consumption used in a building divided by the gross fl oor area in square meter. (http://www.sciencedirect.com, 2015)The whole Building EPI (without credit for renewable energy credits) for NZEB is 78.4 kWh/m2. The EPI break up by each end use is monitored and provided below:

Building HVAC EPI - 45.3 kWh/m2 includes energy consumption by air conditioning equipment to maintain indoor space temperature and indoor air

quality (including removal of heat dissipated by research equipment in the space);

Ambient Lighting EPI - 0.3 kWh/m2 includes energy consumption by artifi cial ambient lighting devices;

Plug Loads EPI - 4.5 kWh/m2 includes energy consumption by computers, personalized fans, and task lights;

Research Equipment EPI - 28.4 kWh/m2 includes energy consumption by research instruments such as envelope characterization devices.

Time16:00 hours

11:00 hours

Very Comfortable Just Comfortable Just Uncomfortable Very Uncomfortable Missing Data


08CONCLUSIONThe process of designing the net zero energy building at CEPT allowed all stakeholders involved to partake in a real life integrated design case study and realize it within an academic environment. It also allowed for a unique academia-practice-industry partnership where the academicians were able to defi ne a theoretical problem and identify new avenues for research. Also, the professional experts expanded their boundaries of problem solving by providing practical solutions. Pre-design analysis helped in establishing set goals, make informed decisions, optimize performance to achieve 78% energy savings and after construction, operate the building with an understanding of the EUI budget and impact of operational decisions.

There were multiple challenges faced in the design and construction of the NZEB. In order to improve the building envelope, exterior insulation was an important strategy. But it did not align with the exposed brick and concrete aesthetic of the other buildings on campus. This issue was resolved by providing an additional brick layer on the external surface of the insulation. This had the added advantage of increasing the thermal mass of the NZEB and helped operate the building in mixed mode along with night time ventilation.

Glazing at the scale of the NZEB building is typically done using single pane glass with steel frame. To achieve the desired thermal performance for the double glazed units (DGUs), aluminum frame with thermal break was considered and then rejected due to cost. Instead, uPVC frame was selected with a dark veneer wood fi nish; window dimensions were measured and orders were placed only after the walls and fl oors slabs had been completed on site. Clearstory frame was removed to get more visible light transmission (VLT) and the glazing was fi xed with sealants only.

The sloped RCC roof had complex steel reinforcement and laying the radiant cooling pipe was a challenge. This was solved by using non-structural radiant panels in the interior. Non-structural radiant cooling also provides better control, faster response time and poses a reduced risk of water leakage compared to structural radiant cooling. It also allows greater fl exibility to change internal space layouts. This

radiant cooling approach allowed better cash fl ow management since the money for the radiant system was not required at the time of RCC casting. The sloping roof and low ceiling height in certain areas could not accommodate ceiling fans. Therefore, pedestal fans were used to generate high air speeds during mixed mode operation. The effi cient envelope and lighting design reduced the cooling loads. In addition, the radiant system needed 14-16˚C supply water which reduced the chiller load to such an extent that it was a challenge to fi nd a modulating chiller of 8TR capacity. It had to be imported from outside India.

An additional challenge was to achieve the net zero goal with a program that dictated that the building be an experimental set-up or a living laboratory. An NZEB needs precision and refi nement while one must allow for wide ranges of operational parameters for experimentation and they may result in a confl ict in design and operation. The need for experimentation has led to the use of multiple systems leading to what may be considered ‘over-designed’ and expensive but it is envisioned to help optimize the cost for such buildings in future from the knowledge it will generate and help make them aff ordable.

CEPT NZEB also revealed the feasibility of designing buildings to operate in mixed-mode in a hot and dry climate like that of Ahmedabad. It demonstrates that high performance buildings do not need to look ‘diff erent’ from the norm and that common sense and conventional architectural language allows for a range of possibilities of aesthetic expressions for such buildings. Another observation that was made during the design and construction of the CEPT NZEB was that there is an abundance of technological solutions available for building envelop, HVAC and lighting but most of them are not appropriate for small buildings. There is a potentially rich market in India for technologies that could work at a small scale to make high performance buildings. Lastly, the owners felt that the concept of ‘return on investment’ was not the right way to look at the economics of an NZEB because such buildings use minimal or no energy. That means potentially low savings in the long term as compared to a business-as usual building. (Rawal, Vaidya, Manu, & Shukla, 2015)


References

Behera, A. R., Rawal, R., & Shukla, Y. (2016). Strategic framework for Net Zero Energy Campus in India: A case of CEPT University Campus. SET (p. 21). SET.

CEPT, & ECO-III, U. (2010). Pre-Read document for CEPT REEC NZEB Charette. Ahmedabad: CEPT University. Clanton, N. (2011). USAID ECO-III Electric Lighting Preliminary Design. USAID ECO-III. http://cept.ac.in/about/cept-university. (2017, December 06). http://cept.ac.in/about/cept-university.

Retrieved from http://cept.ac.in/: http://cept.ac.in/about/cept-university http://cept.ac.in/center-for-advanced-research-in-building-science-energy-carbse. (2017, December 06).

http://cept.ac.in/center-for-advanced-research-in-building-science-energy-carbse. Retrieved from http://cept.ac.in: http://cept.ac.in/center-for-advanced-research-in-building-science-energy-carbse

http://cept.ac.in/cept-research-development-foundation-crdf. (2017, December 06). http://cept.ac.in/cept-research-development-foundation-crdf. Retrieved from http://cept.ac.in: http://cept.ac.in/cept-research-development-foundation-crdf

http://www.carbse.org. (2017, December 6). http://www.carbse.org. Retrieved from http://www.carbse.org: http://www.carbse.org

http://www.sciencedirect.com. (2015, April). http://www.sciencedirect.com. Retrieved from http://www.sciencedirect.com: http://www.sciencedirect.com/science/article/pii/S1364032114010703

Rawal, R., Vaidya, P., Manu, S., & Shukla, Y. (2015). Divide by net-zero: Infi nite potential or calculation error? A quasi-academic design and construction project in India. PLEA 2015 (p. 9). Bologna, Italy: PLEA.

Roederer, D., Sanders, D., & Clanton, N. (2011). USAID ECOIII Daylighting. ECO III, USAID. Taniguchi, T. (2011). Proposed Thermal Comfort Criteria. Built Ecology. The Weidt Group, T. (2011). Introductory Meeting materials. Ahmedabad: TWG. TWG. (2011). Building Massing Analysis Results Report: NZEB at CEPT. Ahmedabad: The Weidt Group. TWG. (2011). Daylighting Analysis Results Meeting: Energy Design Assistance. The Weidt group. TWG. (2011). Energy Design Assistance. Ahmedabad: TWG. TWG. (2011). HVAC Analysis results report - Revised draft. Ahmedabad: TWG. TWG. (2011). Preliminary Thermal Comfort Analysis results report. Ahmedabad: TWG. UNEP. (2014). TRANSFORMING UNIVERSITIES INTO GREEN AND SUSTAINABLE CAMPUSES : A TOOLKIT FOR

IMPLEMENTERS. UNEP. Vaidya, P., & Ghatti, V. (2017). Mixed-Mode Net-Zero Building in India. Building Simulation 2017. San Franciso.


AnnexuresAnnexure 1: CEPT Campus map

P Parking

C Cafeteria

FA Faculty of Architecture

Sagra basement

FP Faculty of Planning

Auditorium

Computer Lab

Administration Area

FT Faculty of Technology

FD Faculty of Design

OFFICES Student Services

Admission Offi ce

Career and Alumni Services

Outreach Service

Summer Winter School Offi ce

UG Offi ce

PG Offi ce

Doctoral Offi ce

Exchange Programs Offi ce

NZEB Net Zero Energy Building

01 CEPT Canteen

02 CEPT Stores

Stationary Shop

Printing Shop

03 Kanoria Centre for Arts

04 Hutheesing Art Centre

05 Vikram Sarabhai Community Science Center

06 CEPT Workshops (Old)

07 Hussain Doshi Gufa

08 Herwitz Gallery

09 GIDC Bhavan 51Nzeb Report - December 2017

Annexure 2: Meters details# Meter Name Purpose Action End Use

1 Power Plug DB Building Operations Measure Electricity consumed by use of computers and laptops, printers, fans, task lights

2 Lighting DB Building Operations Measure Electricity consumed by use of lights

3 Equipment Panel Research Equipment Measure, Monitor and Control

Electricity consumed by use of equipment (Includes Single Patch Sky Simulator, Guarded Hot Box, Solar Calorimeter, Thermal Comfort Chamber, Hygrothermal Characterization Facilities, Lasercomp Fox 600 and NeslabTF900 Chiller, Spectrophotometer, Fourier Transform Infra-Red Spectrometer (FTIR), Air Leakage Chamber, Stand Alone Data Loggers, Indoor Air Quality Handheld Meters, IAQ meter for Instantaneous measurements, Surface Temperature Measurements RTD-PT100, SLR luminance measurements, Weather Station, Universal light monitor)

4 APFCR (Automatic Power Factor Controller Relay)

- Measure Electricity consumed by charging capacitor bank which is used to improve or maintain the total power factor

5 Main Incomer Building Operations and Research Experiments

Measure and Monitor

Total electricity consumed in the building (Includes all the meters which measure or monitor electricity consumed by building systems or research equipment)

6 Sub Incomer NA NA NA (Combination of few meters)

7 Incomer Solar Building Operations and Research Experiments

Measure Electricity generated by solar panels

8 HVAC Panel Building Operations and Research Equipment

Measure, Monitor and Control

Electricity consumed for all HVAC systems and sub-systems (Includes TCC Main AHU, DX Scroll, VRV Outdoor, TCC Chiller, Radiant Chiller, Primary Pump, TCC Personal AHU, DOAS)

9 DX Scroll Building Operations and Research Equipment


Electricity consumed by use of centralized HVAC system in the basement

10 DOAS Building Operations and Research Equipment


Electricity consumed by use of centralized HVAC system in the basement

11 VRV Outdoor Building Operations Measure, Monitor and Control

Electricity consumed by use of 1 outdoor and 8 indoor HVAC units for fi rst and mezzanine fl oor

12 Radiant Chiller Building Operations Measure, Monitor and Control

Electricity consumed by use of Radiant Chiller

13 Primary Pump Building Operations Measure, Monitor and Control

Electricity consumed by use of primary pump to supply water to all the radiant panels

14 TCC Main AHU Research Equipment Measure, Monitor and Control

Electricity consumed by main Air Handling Unit of Thermal Comfort Chamber

15 TCC Chiller Research Equipment Measure, Monitor and Control

Electricity consumed by use of Thermal Comfort Chamber Chiller

16 TCC Personal AHU Research Equipment Measure, Monitor and Control

Electricity consumed by personal Air Handling Unit in Thermal Comfort Chamber


Annexure 3: Testing and Characterization services at CARBSEBuilding Material and Construction CharacterizationThermo-Physical-Optical performance of building material and energy performance of building components play major role in achieving energy effi cient building. CARBSE: CRDF has capabilities to characterize energy performance of building envelop material such as insulation products. CARBSE: CRDF also has competence to test glazing material and fenestration products. A State-of-art facilities is set up at CEPT campus working continuously with industry and research scholars to establish robust database of generic building materials. Combined with component and whole building simulation capabilities, CARBSE: CRDF off ers unique platform to evaluate energy performance of insulating materials, glazing materials, fenestration products, roofi ng products and paints. Presently, CRDF has capabilities to characterize following parameters:

1. Thermal Conductivity to derive R value and U Value 2. Thermal diff usivity and Specifi c heat 3. Air Leakage of Fenestration Products like Windows and

Doors 4. Transmittance, Absorptance, Emittance and Refl ectance

of glazing material 5. Refl ectivity of thermal mirrors.(Curved Surfaces) 6. U-Factor and Solar Heat Gain Coeffi cients of fenestration

products 7. Post Occupancy Evaluation of Building for their

environment and energy performance. 8. Performance evaluation of various materials and

products on the energy demand of building.

CARBSE: CRDF facilitates government initiatives towards implementation of GRIHA and ECBC by providing an unbiased testing facility to all the stakeholders such as architectsdesigners, builders-developers and material processors and manufacturers.

Equipment Material Type of Test Range Standards Sample Size in mm

Heat fl ow meter Insulation Thermal Conductivity

0.01 to W/m.K to 0.2 W/m.K

ASTM C-518 600 x 600

Thermal Constants Building Materials

ThermalConductivity

0.005 to 500 W/mk Meets ISO standard (ISO/DIS 22007-2.2)

100x100x50

Diff usivity 0.1 to 100 mm2/s

Specifi c Heat Up to 5MJ/m3K

Spectrophotometer(With angular measu rement facility)

Glazing Optical Properties

UV / VIS and NIR ISO 9050/EN 410/ ASTM E 903

100×100 (Max. thick. 16)

60×60 (Max.thick. 16)

FTIR using Set Glazing Emissivity IR (Approx. 1300 nm – 44000 nm) EN 673 100×100 60 x 60

Air Leakage Chamber

Fenestration Air Leakage Rate

- NFRC 400, ASTM E 283

Windows : 1200 x 1500, Curtain Walls: 2000 x 2000

Solar Caloriemeter Fenestration SHGC - NFRC 201 1500 x 1500

Guarded Hot Box Wall / Window U Value 0.1 to 5 W/m2k ASTM C 1363 1000 x 1000 x upto 300

Single Patch Sky Simulator (SPSS)

Scaled architectural Models

Daylighting 5 to 100000 lux - 1200 x 1200 xupto 450

Mirror box Scaled architectural Models

Daylighting 0.001 to 1 daylight factor

- 2000 x 2000 x upto 600

Environmental Chamber

Building Materials

Sorption Isotherm

Temperature range of +15.6°C to +37.8°C and a humidity range of 40% to 98% RH as limited by a +4.5° C dew point temperature.

ASTM C1498 having mass more than 10g

Pressure Plates Building Materials

Moisture retention Curve

Humidity ≈ 95 to 100% RH

ASTM C1699 fi ve pieces of approx 15cm2having thickness as minimal as possible ≈ 5mm

Vapometer Cups and Environmental Chamber

Paper, Plastic fi lms or sheet materials

Water Vapor Transmission

Temperature range of +15.6°C to +37.8°C and a humidity range of 40% to 98% RH as limited by a +4.5° C dew point temperature.

ASTM E96/E96M

Thickness should be less than 5mm Diameter in Between 65 mm to 75mm

Water Bath masonry materials, plaster and insulating material

Water Absorption Coeffi cient

- ASTM C1794

Area of specimen must be greater than 50cm 2100mmX 100mm Preferable Thickness should be more than 5mm


Testing Characterization facilities

Single Patch Sky SimulatorCARBSE’s Single Patch Sky Simulator system consists of

a turntable, mirror and Fresnel lamp. By emulating one

sky patch out of the total 145 virtual divisions with equal

area of the sky dome, as per Tregenza’s model, a building

model placed on the turntable can be rotated so that the

lamp is directed from each of the sky dome’s 145 divisions,

and illuminance levels can taken. These measurements are

then aggregated so that they accurately refl ect the daylight

performance of the space under the whole sky dome. The

advantage of this is that because the measurements are

taken according to 145 patches, once measured physically

only once, the eff ective sky can be altered to simulate any

sky condition simply by adjusting the weightage of individual

patches, and calculating the eff ect on the building’s

illuminance levels.

Guarded Hot BoxA Guarded Hot Box is used to test the thermal performance

of non-homogenous specimens, such as complex wall

assemblies, cavity walls, ventilated shaded wall assembly

or walls with phase change materials (PCM). It determines

the amount of heat transfer through a given material or

assembly of various materials. This is done by controlling the

temperature on both sides of the material and minimizing

the extraneous heat transfers other than those through the

given material, which can be used to determine the thermal

transmittance of a homogenous as well as non-homogenous

specimen, and can test a specimen with a maximum thickness

of 350mm. The metering chamber is cooled using chiller

and the guard chamber is maintained at same temperature

using an HVAC system. The climatic chamber is maintained at

higher temperature using electric coils. Surface, water and

air temperature sensors are placed for temperature control

along with humidity (RH), pressure, and air velocity sensors

placed at equal distances.

Solar CalorimeterThe solar calorimeter measures the solar gain through

fenestration products. This is the fundamental test by which

the solar gains through the window assembly of any such

components can be measured. It can also be used for the

measurement of the solar effi ciency of photo voltaic cells

used in Solar PV panels. The solar calorimeter is an insulated

enclosure designed to permit the continuous introduction

and extraction of a measured fl ow of fl uid mass and equipped

with an empty aperture into which a fenestration system is

inserted for characterization. The main components of this

equipment include room side metering chamber, guard

chamber, surround panel for installing test specimen,

calibration panel, heliostat and enclosure.

Thermal Comfort ChamberThe Thermal Comfort Chamber (TCC) is a chamber sized

6m x 5m x 3m, which can precisely simulate a wide range of

indoor environmental conditions with temperatures ranging

from 15°C to 40°C and relative humidity from 16% to 95%,

along with changing air distribution patterns and speed. This

particular capability is useful for Indian studies because it

allows researchers to measure the impact of air velocity, a

necessary criteria in a context dependent on the use of fans

for cooling. These conditions are maintained and monitored

by sophisticated air conditioning systems and control

devices. The purpose of the TCC is to conduct experiments

to evaluate the impact of various indoor environmental

conditions on occupant comfort, productivity, and wellbeing.

People participating in the research would sit on four

workstations in the TCC and experience thermal conditions

set by the research team.

Hygrothermal Characterization FacilitiesCARBSE employs hygrothermal test facilities, which employ

three types of test for material characterization. The fi rst

determines the sorption isotherm, the second derives water

vapor transmission, and the third quantifi es water uplift

characteristics due to capillary action. The material properties

derived from these tests help in calculating the water content

of building materials subjected to various temperatures,

pressure and RH conditions. Such characterization aids the

understanding of moisture migration occurring in opaque

building assemblies, which impacts structural stability,

indoor air quality and energy demand for the maintenance

of desired indoor conditions.

Lasercomp Fox 600 and NeslabTF900 ChillerThe lasercomp fox 600 is used to test the Thermal

Conductivity and characterization of materials. The Thermal

Conductivity of a specimen is determined by measuring the

Heat Flux, specimen thickness, and temperature diff erence

across the specimen. This microprocessor based instrument

carry out tests according to ASTM C 518 and ISO 8301.

Materials like PU Foam, Insulating Material from Industry,

Thermocol, Formular, Expanded and Extruded Polystyrene,

glass wool sandwiched between two plywood sheets,

Styrofoam, etc. can be characterized. Specimen size 600mm

x 600 mm and of thicknesses upto 200 mm are characterized

for the thermal conductivity range from 0.01 to W/m.K to

0.2 W/m.K.

SpectrophotometerSpectrophotometer is a photometer (a device measuring

light intensity) that can measure intensity as a function

of colour (or more specifi cally the wavelength) of light.


Spectrophotometer provides the facility for characterization

of optical properties of glazing materials, architectural

materials and systems of relevant to energy transfer in fl at

specular glazing materials. The glazing may be monolithic,

coated, with applied fi lm, laminated, etc. The Solar

Absorbtence, Refl ectance and Transmittance of material

are determined using Spectrophotometer and Integrating

Spheres. The tests are performed in accordance with EN

410 and ISO 9050. Specimen size 100mm x 100 mm and

of thicknesses is compensated are tested for the optical

properties.

Fourier Transform Infra Red Spectrometer (FTIR)The emissivity of glazing and architectural materials is

measured in Infra Red (IR) range (Approx. 1300 nm – 44000

nm) by Fourier Transform Infra Red Spectrometer (FTIR).

Fourier transform spectroscopy is a measurement technique

whereby spectra are collected based on measurements

of the coherence of a radiative source, using time domain

or space domain measurements of the electromagnetic

radiation or other type of radiation. It can be applied to a

variety of types of spectroscopy (FTIR, FT-NIRS). The tests

are performed in accordance with EN 673.Specimen size

more than 60mm x 60mm of thicknesses is compensated are

tested for emissivity.

Air Leakage ChamberAir Leakage Chamber is used to determine the air-leakage

rates of windows, doors and curtain walls. NFRC 400

document based on ASTM E 283 determines the testing

procedure. Air leakage chamber is not of the shelf-ready

to use equipment- it needs to be constructed according

to the use. The Air leakage chamber will help in evaluating

the relative performance of various fenestration products.

ASTM E 283 is a laboratory test method that has been used

for many to measure air leakage rated under controlled

conditions. Air leakage chamber will help to evaluate present

construction practices as well as new improved construction

practices.

Stand Alone Data LoggersData loggers are useful equipments to monitor

environmental conditions inside and outside buildings. It

can log data for long time (up to 3 years) at regular defi ned

intervals for temperature, humidity, luminance and also if

needed can measure CO/CO2 with additional probe. The

data loggers measures the temperature range from -20° C

to 70°C, Relative humidity of 5% to 95%, and light intensity

from 1 to 4500 foot candles.

Indoor Air Quality Handheld MetersIndoor air quality meters can help in conducting Post

Occupancy Evaluation studies as well as help in determining

user perceive thermal comfort standards. These handheld

meters are capable of logging as well as taking instantaneous

measurements for environmental parameters.

IAQ meter for Instantaneous measurementsIndoor air quality meters can help in conducting Post

Occupancy Evaluation studies as well as help in determining

user perceive thermal comfort standards. These handheld

meters are capable of logging as well as taking instantaneous

measurements for environmental parameters.

Surface Temperature Measurements RTD-PT100Basic function of the RTD sensor is to measure surface

temperature. By using these RTD sensors the thermal

performance of materials and thermal lag of building can be

studied and understood. Experimental set up to fi nd out the

U-Value of material, assemblies and components.

SLR luminance measurementsA light meter is used to measure the amount of light. It

helps in conducting Post Occupancy Evaluation studies. This

instrument help in color correction functions – luminance

ratio and peak luminance measurements.

Weather StationThe micro weather station with a four-sensor data logger

helps in multi-channel monitoring of microclimates in one or

more locations and it uses a network of smart sensors for

taking measurements. Key features of the smart sensors

are Automatic detection, Easy expansion, Digital network,

Weatherproof. The micro sensors also helps in optimizing

Lifecycle Energy Performance of commercial and residential

Building (which measures temperature, RH, Rain, wind

speed and direction, soil moisture, solar radiation and

photosynthetic active radiation (PAR).

Universal light monitorLight meter is used for conducting Post Occupancy Evaluation

studies, daylight penetration studies and need for electric

light and related energy usage in conditioned environments.

These are the handheld meters capable of logging as well as

taking instantaneous measurements for lux level.


Center for Advanced Research in Building Science and EnergyCEPT University, K.L. Campus,Navarangpura, Ahmedabad 380 009, IndiaPhone: +9179 2630 2470, Ext: 383Website: www.carbse.orgEmail: [email protected]

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